Dura Auto Systems v. CTS Corporation ( 2002 )


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  • In the
    United States Court of Appeals
    For the Seventh Circuit
    No. 01-1081
    Dura Automotive Systems of Indiana, Inc.,
    formerly known as Excel Corporation,
    Plaintiff-Appellant,
    v.
    CTS Corporation,
    Defendant-Appellee.
    Appeal from the United States District Court
    for the Northern District of Indiana, South Bend Division.
    No. 93 C 119--Robert L. Miller, Jr., Judge.
    Argued October 26, 2001--Decided April 4, 2002
    Before Posner, Manion, and Diane P. Wood,
    Circuit Judges.
    Posner, Circuit Judge. In 1981 the Main
    Street Well Field, part of the water
    supply of the city of Elkhart, Indiana,
    was discovered to be contaminated by TCE
    and other volatile organic compounds that
    are used as industrial or household
    solvents. Twelve years later the EPA,
    having cleaned up the contamination, sued
    several entities under the Superfund
    statute (Comprehensive Environmental
    Response, Compensation, and Liability Act
    of 1980, 42 U.S.C. sec.sec. 9601 et
    seq.), including Dura Automotive Systems
    (actually its predecessor, Excel, but
    that’s a detail we can ignore), to
    recover the costs of the clean-up. Dura
    impleaded CTS Corporation, claiming that
    it was responsible for some of the
    pollution and should therefore be
    required to reimburse a share of Dura’s
    clean-up expense. The EPA’s claims were
    settled or otherwise resolved, leaving
    only Dura’s third-party claim against
    CTS. At the behest of CTS and on the
    authority of Daubert v. Merrell Dow
    Pharmaceuticals, Inc., 
    509 U.S. 579
    , 592-
    93 (1993), the district judge
    disqualified Dura’s sole expert witness;
    and then, holding that the remaining
    evidence was insufficient to create a
    genuine issue of material fact, he
    granted summary judgment for CTS.
    The groundwater stream beneath CTS’s
    plant, a plant that manufactures plastic
    by a process that employs volatile
    organic compounds, is 3,000 feet west of
    the Main Street Well Field and runs
    generally south rather than east. In
    contrast, Dura’s plant, which also uses
    these chemicals, is across the street
    from the well field and it was Dura
    rather than CTS that was a defendant in
    the EPA’s suit. But conceivably some of
    the groundwater beneath CTS’s plastics
    plant had seeped into the well field back
    in the late 1970s or early 1980s,
    contributing to the pollution discovered
    in 1981. This could only be so, however,
    if CTS’s plant was within the well
    field’s "capture zone" (in other words,
    its catchment basin), the area within
    which groundwater, if present, could be
    expected to flow to the well field. The
    size of the capture zone would depend on
    such things as the porosity of the soil
    and--a factor particularly emphasized by
    the parties--the rate at which the well
    field pumps water. The more it pumps, the
    larger the capture zone, because the
    removal of groundwater beneath the field
    causes groundwater to be drawn in by
    gravity from other areas.
    To use porosity, pumping, and other data
    that bear on the size of the capture zone
    to map the zone, hydrogeologists build
    mathematical models consisting of systems
    of equations that show changes in the
    boundaries of the zone as functions of
    changes in the causal variables, such as
    porosity. These models are used to
    predict the future size of capture zones
    but they can also be used to estimate the
    size of a capture zone in the past if the
    requisite historical data on the causal
    variables are available, here, for
    example, data on pumping rates in the
    late 1970s. The parties agree that
    without such a model Dura could not prove
    its case against CTS. A consulting firm
    retained by the EPA in the original suit
    had placed CTS’s plant outside the well
    field’s capture zone, and if this
    placement stood, CTS could not have been
    a source of the pollution of the Main
    Street Well Field and so Dura would have
    no right of reimbursement by CTS.
    Dura designated as its one and only
    expert witness Nicholas Valkenburg, a
    hydrogeologist who works for a consulting
    firm called Geraghty & Miller. At his
    deposition, however, Valkenburg admitted
    that he was not an expert in mathematical
    models of groundwater flow and that the
    modeling on which he relied for his
    conclusion that CTS’s plastics plant was
    indeed within the well field’s capture
    zone had been done by other employees of
    Geraghty & Miller, using two models,
    QuickFlow and SLAEM.
    When CTS moved that Valkenburg be barred
    from testifying and that Dura’s third-
    party claim be dismissed, Dura responded
    with affidavits from four employees or
    ex-employees of Geraghty & Miller who had
    worked on the Dura project. These
    professional groundwater-flow modelers
    attested that the models they had used,
    QuickFlow and SLAEM, were reliable and
    were appropriate for determining the well
    field’s capture zone in the late 1970s.
    CTS moved to strike the affidavits under
    Fed. R. Civ. P. 37(c)(1) on the ground
    that Dura’s disclosure of additional
    expert witnesses, required by Rule
    26(a)(2), was untimely, since the
    deadline for filing expert reports had
    expired six months previously. The
    district judge granted the motion to
    strike, and holding that without the
    affidavits there was insufficient
    evidence of the reliability of the
    models, ruled that Valkenburg could not
    testify--and without Valkenburg’s
    testimony, Dura had no case. So the judge
    granted summary judgment for CTS.
    If the affidavits were properly struck,
    Valkenburg’s testimony indeed lacked an
    adequate foundation. For while there is a
    smattering of other evidence about the
    models (for example, that they are widely
    used), it does not establish their
    appropriateness for mapping the well
    field’s capture zone 20-odd years ago.
    Dura argues, however, that even if
    properly struck as untimely expert-
    witness reports, so that Dura would not
    be able to call the authors as expert
    witnesses at trial, the affidavits
    remained usable as evidence that the
    QuickFlow and SLAEM models were indeed
    suitable for the purpose to which
    Valkenburg sought to put them. This is
    true to the extent that the affidavits
    merely attest to facts or opinions on
    which Valkenburg would be permitted to
    rely, such facts as that SLAEM had been
    peer- reviewed. But to the extent that
    the affidavits contain evidence that
    would have to be presented at trial by an
    expert witness or witnesses other than
    Valkenburg in order for Dura to withstand
    a motion for judgment as a matter of law,
    Dura’s failure to have made timely
    disclosure of their expert opinions
    invited application of Rule 37(c)(1) to
    bar the authors of the affidavits, or any
    other expert for that matter, from
    testifying along with Valkenburg.
    NutraSweet Co. v. X-L Engineering Co.,
    
    227 F.3d 776
    , 785-86 (7th Cir. 2000);
    Salgado by Salgado v. General Motors
    Corp., 
    150 F.3d 735
    , 741 n. 6 (7th Cir.
    1998); Lohnes v. Level 3 Communications,
    Inc., 
    272 F.3d 49
    , 60-61 (1st Cir. 2001).
    We must decide whether the district
    judge was reasonable in regarding the
    affidavits as experts’ reports that Dura
    had failed to disclose to CTS in a timely
    fashion rather than merely as
    attestations that show that Valkenburg
    was competent to report the results of
    the modeling exercises undertaken by
    other employees of the consulting firm.
    As the form in which we have stated the
    question makes clear, we must give the
    benefit of the doubt to the district
    judge. General Electric Corp. v. Joiner,
    
    522 U.S. 136
    , 141-43 (1997); NutraSweet
    Co. v. X-L Engineering 
    Co., supra
    , 227
    F.3d at 786; Yeti by Molly, Ltd. v.
    Deckers Outdoor Corp., 
    259 F.3d 1101
    ,
    1106 (9th Cir. 2001).
    An expert witness is permitted to use
    assistants in formulating his expert
    opinion, and normally they need not
    themselves testify. United States v.
    Bramlet, 
    820 F.2d 851
    , 855-56 (7th Cir.
    1987); United States v. Lawson, 
    653 F.2d 299
    , 301-02 (7th Cir. 1981). The opposing
    party can depose them in order to make
    sure they performed their tasks
    competently; and the expert witness can
    be asked at his deposition whether he
    supervised them carefully and whether his
    relying on their assistance was standard
    practice in his field. If the requisite
    assurances are forthcoming, the
    assistants’ work need not be introduced
    into evidence. Rule 703 of the Federal
    Rules of Evidence is explicit that "the
    facts or data in the particular case upon
    which an expert bases an opinion or
    inference may be those perceived by or
    made known to the expert at or before the
    hearing. If of a type reasonably relied
    upon by experts in the particular field
    in forming opinions or inferences upon
    the subject, the facts or data need not
    be admissible in evidence in order for
    the opinion or inference to be admitted."
    Analysis becomes more complicated if the
    assistants aren’t merely gofers or data
    gatherers but exercise professional
    judgment that is beyond the expert’s ken.
    (They needn’t, of course, be assistants.
    We use the term because that seems the
    best description of the relation of the
    four affiants to Valkenburg, but it would
    make no difference if they were
    independent experts.) Now it is common in
    technical fields for an expert to base an
    opinion in part on what a different
    expert believes on the basis of expert
    knowledge not possessed by the first
    expert; and it is apparent from the
    wording of Rule 703 that there is no
    general requirement that the other expert
    testify as well. The Committee Notes to
    the 1972 Proposed Rule 703 give the
    example of a physician who, though not an
    expert in radiology, relies for a
    diagnosis on an x-ray. We too do not
    "believe that the leader of a clinical
    medical team must be qualified as an
    expert in every individual discipline
    encompassed by the team in order to
    testify as to the team’s conclusions."
    Walker v. Soo Line R.R., 
    208 F.3d 581
    ,
    589 (7th Cir. 2000); see also United
    States v. Smith, 
    869 F.2d 348
    , 355 (7th
    Cir. 1989); Ferrara & DiMercurio v. St.
    Paul Mercury Ins. Co., 
    240 F.3d 1
    , 8-9
    (1st Cir. 2001). But suppose the
    soundness of the underlying expert
    judgment is in issue. Suppose a thoracic
    surgeon gave expert evidence in a medical
    malpractice case that the plaintiff’s
    decedent had died because the defendant,
    a radiologist, had negligently failed to
    diagnose the decedent’s lung cancer until
    it was too advanced for surgery. The
    surgeon would be competent to testify
    that the cancer was too advanced for
    surgery, but in offering the additional
    and critical judgment that the
    radiologist should have discovered the
    cancer sooner he would be, at best, just
    parroting the opinion of an expert in
    radiology competent to testify that the
    defendant had x-rayed the decedent
    carelessly. The case would be governed by
    our decision in In re James Wilson
    Associates, 
    965 F.2d 160
    , 172-73 (7th
    Cir. 1992), where the issue was the state
    of repair of a building and "the expert
    who had evaluated that state--the
    consulting engineer--was the one who
    should have testified. The architect [the
    expert who did testify] could use what
    the engineer told him to offer an opinion
    within the architect’s domain of
    expertise, but he could not testify for
    the purpose of vouching for the truth of
    what the engineer had told him--of
    becoming in short the engineer’s
    spokesman." See also TK-7 Corp. v. Estate
    of Barbouti, 
    993 F.2d 722
    , 732 (10th Cir.
    1993). It is the same here. Valkenburg
    could have testified that the well field
    was contaminated by volatile organic
    compounds and that if CTS’s plastics
    plant was within the well field’s capture
    zone some of the contamination may have
    come from that plant. It does not follow
    that he could testify that the plant was
    within the well field’s capture zone.
    The Daubert test must be applied with
    due regard for the specialization of
    modern science. A scientist, however well
    credentialed he may be, is not permitted
    to be the mouthpiece of a scientist in a
    different specialty. That would not be
    responsible science. A theoretical
    economist, however able, would not be
    allowed to testify to the findings of an
    econometric study conducted by another
    economist if he lacked expertise in
    econometrics and the study raised
    questions that only an econometrician
    could answer. If it were apparent that
    the study was not cut and dried, the
    author would have to testify; he could
    not hide behind the theoretician.
    We must decide whether the district
    judge was reasonable in concluding that
    this was such a case. The answer lies in
    the four affidavits of the Geraghty &
    Miller employees who did the modeling
    that mapped the capture zone. The
    affidavits are much alike, and we can
    confine attention to those of James
    Rumbaugh, who developed the QuickFlow
    model, and of Eric Evans, a current
    employee of Geraghty & Miller. Rumbaugh’s
    affidavit confirms that QuickFlow is a
    system of equations for mapping a capture
    zone from data causally related to the
    size of the zone. It acknowledges that
    modeling groundwater flow (the capture
    zone being, remember, the area from which
    the groundwater that polluted a given
    site could have flowed) "is inherently
    not the most precise of scientific tools"
    because "one never possesses complete
    geotechnical information." (So this is
    not like taking an x-ray.) As a result,
    "the process of constructing a valid and
    useful groundwater model is an iterative
    process that requires the exercise of
    sound technical judgment in evaluating
    all available geotechnical data to
    determine what input values should be
    used with respect to each parameter
    utilized in the model." (In other words,
    professional discretion--expertise--is
    involved.) Rumbaugh goes on to say that
    in his experience "most hydrogeologists
    are not experts in modeling"--and we know
    that Valkenburg is not; and groundwater
    modeling is not the sort of thing that a
    lab technician or other subprofessional
    does. Rumbaugh therefore "generally
    work[s] with other hydrogeologists [such
    as Valkenburg] to provide modeling
    results upon which they can rely."
    Rumbaugh states that he is familiar with
    SLAEM and while it is not as
    sophisticated as some groundwater models,
    it is "entirely adequate and appropriate"
    for answering the sort of question posed
    by the present case. That of course is an
    expert opinion. It is also his expert
    judgment (not Valkenburg’s) that "it was
    reasonable and appropriate to use
    QuickFlow" in the case. He calibrated the
    QuickFlow model, that is, compared the
    results it generated with observable
    results for the current period
    (obviously, the accuracy of its map of
    the capture zone in the late 1970s cannot
    be observed). He attests that the kind of
    calibration he did, though visual rather
    than quantitative, is "an accepted
    practice in the modeling community."
    Evans’s affidavit adds that it is his
    "opinion today that the hydrogeologic
    data set available to Geraghty & Miller
    was adequate for the development of a
    groundwater system model that would
    provide reliable information regarding
    the area encompassed by the Well Field
    capture zone under certain conditions"
    and specifically that SLAEM "is a valid
    tool for determining the extent of the
    Well Field ’capture zone’ at various
    times in the past," reflecting
    "reasonable technical judgments" by
    himself, the other affiants, and
    Valkenburg. He explains why SLAEM didn’t
    have to be recalibrated and attests that
    "the use of groundwater models to
    simulate historic conditions (’backward-
    modeling’) is a valid and a commonly
    applied approach" and that "an inherent
    assumption" of SLAEM, namely "that
    groundwater flow is two-dimensional," is
    "valid within the area surrounding the
    [Main Street] Well Field." Obviously,
    these are expert opinions, not
    recitations of cut-and-dried procedures.
    It is apparent from these affidavits
    that Valkenburg’s assistants did not
    merely collect data for him to massage or
    apply concededly appropriate techniques
    in a concededly appropriate manner, or
    otherwise perform routine procedures, and
    that he himself lacks the necessary
    expertise to determine whether the
    techniques were appropriately chosen and
    applied. Remember that there were two
    crucial issues--the map of the capture
    zone and whether, if CTS’s plant was
    within it, how much if any of the
    contamination of the well field was due
    to the groundwater running beneath that
    plant. Valkenburg was not competent to
    opine on the first issue, and without an
    expert opinion on that issue Dura could
    not get to the second and so could not
    prevail.
    We are not hydrogeologists, but we can
    imagine that the assertion that visual
    calibration is an adequate substitute for
    exact measurement, or that groundwater
    flow is "two dimensional" rather than
    three dimensional, would be controversial
    in the relevant community of experts.
    More important than these conjectures is
    Rumbaugh’s reference to the construction
    of a groundwater-flow model as an "itera
    tive process," a fancy way of describing
    tinkering with the original model until
    it yields satisfactory results. There is
    nothing wrong with such tinkering. But we
    must be realistic about expert evidence:
    Geraghty & Miller was hired to provide
    evidence favorable to Dura; so any margin
    of discretion in the construction of the
    groundwater-flow model could be expected
    to be exploited to Dura’s benefit. That
    discretion was exercised not by
    Valkenburg but by Rumbaugh and the other
    affiants, for it was they who constructed
    the model, and the "iterative process" by
    which they did so is beyond the scope of
    Valkenburg’s expertise. The quotations
    that we gave from their affidavits show
    the breadth of the expert discretion that
    they exercised. Without their testimony
    explaining and justifying the discretion
    ary choices that they made, his testimony
    would have rested on air.
    Had Dura merely wanted to use SLAEM and
    QuickFlow to determine the current
    capture zone of the Elkhart well field,
    we might well have a different case; such
    use might be quite routine. Dura wanted
    to use these models to determine the
    capture zone twenty years ago. The
    affidavits make clear that adapting the
    models to that use required a host of
    discretionary expert judgments for the
    affiants, not Valkenburg, to make.
    Dura argues that it could not have
    foreseen that the judge would find
    Valkenburg unqualified to give expert
    testimony in this case and therefore it
    should have been forgiven the untimely
    filing of additional experts’ reports.
    Rule 37(c)(1) states that expert
    testimony may not be presented at trial
    if the expert’s report was not disclosed
    to the other side within the deadline
    unless the party was justified in missing
    the deadline or the untimeliness of the
    disclosure was harmless. As some cases
    fail to note, however, see Miksis v.
    Howard, 
    106 F.3d 754
    , 760 (7th Cir.
    1997); Mid-America Tablewares, Inc. v.
    Mogi Trading Co., 
    100 F.3d 1353
    , 1363
    (7th Cir. 1996); Wilson v. Bradlees of
    New England, Inc., 
    250 F.3d 10
    , 20-21
    (1st Cir. 2001), the rule goes on to
    authorize the judge, "in lieu of this
    sanction . . . [to] impose other
    appropriate sanctions," and this
    authorization implies, as United States
    v. Johnson, 
    228 F.3d 920
    , 926 (8th Cir.
    2000), rightly holds, that a judge’s
    failure to impose a lighter sanction
    might be an abuse of discretion even if
    the party could not show that missing the
    deadline was justified or harmless. Cf.
    Sherrod v. Lingle, 
    223 F.3d 605
    , 612-13
    (7th Cir. 2000). But this is not such a
    case. Not only was there no justification
    for not disclosing to CTS the opinions of
    the other experts--for Dura should have
    known that Valkenburg’s expertise did not
    extend to scientific issues at once
    crucial to the prima facie case and
    likely to be contested. In addition, the
    suit was in its seventh year when the
    judge acted; to have reopened discovery
    to give CTS its crack at the additional
    experts would have extended the
    litigation, and burdened CTS,
    unreasonably. Dura is a substantial firm
    rather than a hapless individual. Its
    reticence about disclosing the other
    experts may have been strategic. At all
    events, in the circumstances the district
    judge could refuse to exercise lenity
    without being thought to have acted
    unreasonably.
    Affirmed.
    DIANE P. WOOD, Circuit Judge, dissenting.
    This case is about whether CTS must help
    Excel pay for some of the costs of
    cleaning up the Main Street Well Field.
    (I prefer to use the name "Excel" for the
    plaintiff, following the practice of the
    district court and both parties; this is
    the same company that the majority calls
    "Dura.") As the majority opinion
    explains, that ultimate question turns
    largely on a highly technical
    determination about the size of the
    Field’s capture zone in the late 1970’s
    and early 1980’s. Hydrogeologists working
    for the Environmental Protection Agency
    (EPA) decided, based on their computer
    models and analysis, that CTS’s main
    factory and plastics plant (the most
    polluted properties in the entire area)
    lay outside the crucial capture zone, and
    thus that CTS need not contribute to the
    cleanup costs. Excel’s expert, Nicholas
    Valkenburg, challenges that
    interpretation of the data. His own
    research places much of the CTS property
    within the capture zone and identifies
    CTS as a major source of the Field’s
    pollution.
    A number of factors account for the
    difference between the EPA’s and
    Valkenburg’s conclusions about the shape
    and size of the capture zone. First,
    based on records from the Elkhart water
    works office, Valkenburg instructed his
    computer modelers, who inputted the data
    used to draw the capture zone and then
    calibrated the models, to increase the
    assumed Field pumping rate to 6 million
    gallons per day (MGD) from the 5 MGD
    figure that the EPA used. Second,
    Valkenburg consulted pond level readings
    made by the U.S. Geological Survey and
    his own employees over a two-decade span
    and lowered the pond recharge rate from 5
    MGD to 4 MGD. Third, Valkenburg adjusted
    the hydraulic convectivity rates used in
    the model. The USGS had determined that
    in different parts of the Field the
    convectivity rate ranged from 80 to 400
    feet per day, but for estimation purposes
    the EPA used a rate of 200 feet per day
    for the entire model. Valkenburg asked
    his modelers to divide the region into
    zones based on available data to
    construct a more sophisticated model.
    It is clear from reading CTS’s brief
    that its principal objection to
    Valkenburg’s research was to these
    adjustments--or, as CTS says more
    pejoratively, to his manipulation of
    these variables based on what CTS
    considers to be inadequate scientific
    foundation. Much of CTS’s four-day
    deposition of Valkenburg was devoted to
    the technical basis for his adjustments
    and estimates. Had a trier of fact in
    this case listened to both Valkenburg and
    the CTS experts and then determined that
    the data utilized by CTS more accurately
    represented the characteristics of the
    Field circa 1980, I would probably have
    little quarrel with such a finding. But
    we are not faced with such a challenge
    today. Indeed, we are not even evaluating
    Valkenburg’s decision to adjust the three
    variables I have mentioned. Instead, the
    district court’s ruling and the
    majority’s opinion focus on a fourth
    difference between the EPA and Valkenburg
    studies: the computer program used by the
    computer modelers to represent the
    capture zone. The EPA used two computer
    programs called GWPATH and FEMSEEP, which
    apparently were not available to the
    general public. CTS argues that is best
    to rely on a "three-dimensional" modeling
    program called MODFLOW, while Excel used
    the "two-dimensional" programs QuickFlow
    and SLAEM. Both the district court and
    the majority believe that Excel’s
    evidence is fatally flawed because
    Valkenburg, who while an expert in
    hydrogeology knows little about the
    technical aspects of hydrogeological
    computer modeling, played almost no role
    in selecting QuickFlow and SLAEM instead
    of MODFLOW or some other program.
    Instead, he left that task to four
    computer modelers employed by Geraghty &
    Miller. This specific decision is what
    then prompted the inquiry in this case
    and the district court’s ruling that
    Excel had failed to comply with the
    dictates of Daubert v. Merrell Dow
    Pharm., Inc., 
    509 U.S. 579
    (1993).
    Since Daubert was decided, the Supreme
    Court has addressed its scope on a number
    of occasions. It confirmed in General
    Electric Co. v. Joiner, 
    522 U.S. 136
    , 141
    (1997), that the abuse of discretion
    standard applies to appellate review of
    decisions applying the Daubert framework.
    In Kumho Tire Co. v. Carmichael, 
    526 U.S. 137
    , 147 (1999), it held that the Daubert
    approach applies to all expert testimony,
    not simply to scientific evidence. And
    recently, in Weisgram v. Marley Co., 
    528 U.S. 440
    , 457 (2000), the Court held that
    a court of appeals has the authority to
    direct entry of judgment as a matter of
    law if it concludes that Daubert requires
    the exclusion of proffered expert
    evidence and the remaining evidence is
    insufficient to support a verdict.
    Moreover, Daubert’s approach has been
    codified in the Federal Rules of
    Evidence, in the form of the revised
    version of Rule 702 that took effect on
    December 1, 2000. The net result of all
    of this is a now well-recognized
    approach. First, we ensure that the
    district court took all of the steps that
    a correct application of the Daubert
    framework (or, where it applies, amended
    Rule 702) requires. That is a legal
    inquiry, for which de novo review is
    proper. See, e.g., United States v. Hall,
    
    93 F.3d 1337
    , 1341-42 (7th Cir. 1996).
    Beyond that, Joiner makes clear that our
    review of particular applications of
    Daubert is under the deferential abuse of
    discretion standard. Dhillon v. Crown
    Controls Corp., 
    269 F.3d 865
    , 869 (7th
    Cir. 2001).
    It is useful at this point to review
    what ought to happen under the Daubert
    framework, because in my opinion the flaw
    in both the trial judge and the
    majority’s analysis comes from a failure
    to follow this framework. A trial judge
    faced with proffered expert testimony
    must initially determine whether the
    proposed expert would be testifying about
    scientific (or other expert) knowledge
    that would assist the trier of fact.
    Here, the proffered testimony is easily
    characterized as scientific, so I will
    limit my discussion to that area.
    Determining whether evidence is
    scientific "entails a preliminary
    assessment of whether the reasoning or
    methodology underlying the testimony is
    scientifically valid and of whether that
    reasoning or methodology properly can be
    applied to the facts in 
    issue." 509 U.S. at 592-93
    . To make this assessment, the
    court must investigate questions such as
    whether the expert’s methodology can be
    and has been tested, whether it has been
    subject to peer review or publication,
    what is its known or potential rate of
    error, and how generally accepted it is
    in the relevant scientific community. 
    Id. at 593-94.
    The majority has jettisoned this
    established framework in its acceptance
    of CTS’s criticisms of the computer
    programs Valkenburg used. Under the
    framework, CTS should have challenged
    these programs through the use of its own
    experts. Presumably the CTS experts would
    have argued that QuickFlow and SLAEM are
    unreliable for backwards modeling (that
    is, predicting past conditions instead of
    projecting future conditions) or that a
    hydrogeologist would not reasonably rely
    on the results yielded from such a model.
    In response, Excel, as the party
    supporting Valkenburg’s methodology,
    would have been able to introduce
    additional expert testimony or written
    materials, since hearsay is admissible at
    a Daubert hearing and the rules of
    evidence do not apply. 
    Daubert, 509 U.S. at 593
    n.10.
    No such Daubert hearing occurred in this
    case. CTS has offered no testimony from
    any experts even to hint that QuickFlow
    and SLAEM are scientifically
    questionable. In contrast, as I discuss
    below, Excel offered considerable support
    for the proposition that they are widely
    accepted in the relevant expert community
    for substantive (that is, non-litigation)
    work. Moreover, the district court never
    convened a hearing on the issue; instead,
    it simply struck the supporting
    affidavits proffered by the computer
    modelers themselves. At this point, the
    majority criticizes Excel for not naming
    the modelers earlier, but it is not at
    all obvious that this should have been
    done. No one else had delved that deeply
    into the background programs and
    materials from which the hydrogeologists
    were forming their opinions; to the
    contrary, both the EPA and the other
    principal defendant also disclosed only a
    single expert hydrogeologist as a
    witness. While it is possible that these
    individuals are expert computer modelers,
    that seems unlikely.
    I am deeply concerned that the
    majority’s approach will have the effect
    of transforming--in a manner
    uncontemplated by and unauthorized by
    Rule 702--the way in which litigants
    approach the use of expert witnesses in
    all kinds of cases. All experts, and all
    people for that matter, rely on the
    expertise of others. Cautious parties
    will feel compelled to engage in
    something like an infinite regression of
    the naming of experts. Expert 1 may have
    relied on something prepared using the
    expertise of Expert 2, who in turn relied
    on the expertise of Expert 3, and on out
    until we reach Expert N. There is no
    reason to assume that Experts 2, 3, and
    others are "hiding behind" Expert 1, if
    the information they produce is commonly
    relied upon by people in the field of
    Expert 1. Indeed, Rule 702 permits
    exactly this kind of reliance, as I
    explain later. Thus, it makes no
    difference to my analysis whether we
    consider the computer modelers to be
    "mere" technicians or experts in their
    own right. The critical question is
    instead whether CTS ever introduced any
    evidence tending to show that a
    hydrogeologist would not commonly rely on
    their choice of a computer model.
    Recall that here Valkenburg ordered his
    modelers to increase the pumping rate
    used in the models based on a review of
    the Elkhart city water records. CTS also
    argued below that this evidence was
    suspect because Valkenburg himself did
    not inspect the water records, leaving
    that chore to his assistants, and because
    Valkenburg testified that he did not know
    how Elkhart’s water records were kept.
    While the majority might decide that
    these tasks lack discretion and do not
    require testimony at trial, another
    district court might take a different
    view of the matter. The radiologist, the
    computer modeler, the data collector, the
    Water Department recordkeeper, even the
    lab technician who selects a test tube
    that is not of the highest quality on the
    market all exercise some measure of
    discretion that could conceivably
    influence an expert’s end product. And
    since the expert can never supplement an
    expert report in any way under the
    majority’s approach, the only responsible
    course would be to disclose all of these
    individuals as potential expert witnesses
    and have each submit a comprehensive Rule
    26(b)(2)(B) expert report, fueling ever
    more time-consuming and expensive
    litigation.
    Nothing in Daubert, any of the later
    Supreme Court decisions, or amended Rule
    702 requires any such thing; the Daubert
    approach is designed only to ensure that
    an expert’s methodology is reliable and
    accepted rather than quack science. But
    that one central question was never
    explored here, because as I have already
    mentioned the district court never
    conducted a Daubert hearing or heard a
    single CTS expert opine that Valkenburg
    had made unreliable assumptions or had
    utilized an unaccepted computer program
    in reaching his conclusions about the
    Field capture zone and the migration of
    chemicals from the CTS plastics plant.
    This was a failure of procedure, not a
    discretionary decision about the way to
    apply the Daubert factors in a particular
    situation. I thus regard it as the kind
    of thing this court should review de
    novo. Cummins v. Lyle Indus., 
    93 F.3d 362
    , 367 (7th Cir. 1996). Because the
    district court and the majority’s
    approach drastically modifies the Daubert
    analytical framework, I cannot accept its
    conclusions.
    Turning briefly to the details of the
    Daubert analysis, let me suppose for a
    moment that we should disregard the
    affidavits of the four computer modelers
    who were prepared to testify about the
    general acceptance of the programs on
    which Valkenburg relied. Even without
    those affidavits, the only evidence in
    the record is that SLAEM is a generally
    accepted computer program in the modeling
    community. The program has been used by
    the lead environmental agencies of the
    United States, the Netherlands, and
    Minnesota. It has been published and has
    sold well in commercial markets.
    Valkenburg unequivocally testified that
    SLAEM is widely used by hydrogeologists
    outside the litigation context, a major
    indicator of reliability. 
    Daubert, 509 U.S. at 593
    . (Most lawyers widely use
    computer research programs like LEXIS
    and WestLaw, and they would be competent
    to testify about their general
    acceptance, even if they do not know how
    the programs were written.) Valkenburg
    also noted that his model can be
    validated and calibrated by visually
    comparing its projections to actual
    current water levels, which could help
    determine an error rate. 
    Id. at 594.
    While CTS baldly asserts that
    Valkenburg’s methodology is unreliable
    and the majority "imagines" that
    hydrogeologists might find something
    controversial or suspect about visual
    calibration or two-dimensional modeling,
    CTS has presented no hydrogeologist or
    other scientist to attest to this fact.
    Indeed, the only information we have
    suggests exactly the opposite: Excel
    contends that CTS’s own environmental
    consulting experts used visual
    calibration in constructing their models.
    Even under abuse of discretion review,
    when CTS has offered nothing to challenge
    any of the support offered by Excel, I
    see no possible way to hold that either
    SLAEM or QuickFlow are inherently
    unreliable or that an expert
    hydrogeologist would for some other
    reason not rely on them.
    As a theoretical matter, I have no
    problem with the majority’s proposition
    that a thoracic surgeon in a medical
    malpractice suit cannot testify that a
    radiologist was negligent for failing to
    diagnose lung cancer at an earlier time,
    or that a theoretical economist may not
    serve as a "mouthpiece" for an
    econometrician. But the real question is
    whether those analogies fit the situation
    of a hydrogeologist’s reliance on a
    computer modeler’s choice of a program. I
    think not. The dispute here is far more
    like the x-ray example from the Advisory
    Committee Notes to the 1972 Proposed
    Rules, which permits a physician to rely
    upon x-rays in formulating her
    diagnosis,/1 or, even more
    appropriately, like a case in which the
    opposing party objected to a physician’s
    testimony on the ground that the
    radiologist who took the x-rays relied on
    an x-ray machine that was old,
    antiquated, or in some other way
    inadequate under modern day standards.
    The only objection ever voiced even by
    CTS’s counsel (whose expertise in these
    matters is certainly unproven) is that
    QuickFlow and SLAEM are inferior two-
    dimensional programs that require visual
    calibration and therefore give inaccurate
    and scientifically unsound results.
    Daubert and the Federal Rules of Evidence
    anticipate only a basic inquiry into
    whether an expert physician would
    reasonably rely on a radiologist to do
    her job and use adequate and up-to-date
    technology and whether an expert
    hydrogeologist such as Valkenburg would
    reasonably rely on his computer modelers
    to select an adequate and up-to-date
    computer model to crunch the data
    necessary for him to interpret his
    results. The record shows that he would.
    This does not mean that if a physician
    really did rely on a radiologist who used
    an inferior x-ray machine the results
    could go unchallenged; it means only that
    such potential flaws go to the weight,
    not to the admissibility, of the
    evidence. The party’s opponent would have
    an opportunity to introduce an expert
    radiologist in rebuttal under Rule
    26(a)(2)(C) who could assert that,
    although a physician would normally have
    every right to rely on a radiologist’s
    work, in this specific case that reliance
    was unjustified. But CTS has introduced
    no such expert here. The only evidence in
    the record is that an expert
    hydrogeologist would reasonably rely on
    computer modelers to select appropriate
    computer models and plug in the data the
    hydrogeologist provides to produce
    accurate capture zones.
    In the end, even CTS’s argument makes it
    clear that the dispute here is about
    Valkenburg’s decisions as a
    hydrogeologist, not about the computer
    program he was using. As CTS repeatedly
    noted in its motion before the district
    court, Valkenburg acknowledged in his
    deposition that when he had earlier
    instructed his computer modelers to run
    QuickFlow and SLAEM using the same
    variables that CTS and the EPA had used,
    the CTS plants were not located within
    the capture zone. This indicates that the
    computer program used has little or
    nothing to do with the real dispute in
    this case: the correctness of
    Valkenburg’s expert opinion that the
    pumping, pond recharge, and hydraulic
    convectivity rates were different than
    the EPA had thought. That dispute is all
    about the variables and data that Valken
    burg, not the computer modelers, decided
    to use for the program. Assuming that
    Valkenburg used reliable and generally
    accepted methods in determining those
    variables (another issue never reached by
    the district court) these questions
    should be resolved as a factual matter at
    trial. The fact that the selection of a
    computer program, whether a "two-
    dimensional" or "three-dimensional"
    model, seems largely irrelevant to the
    final analysis also likely explains why
    Excel considered it unnecessary to
    disclose any of its computer modelers as
    expert witnesses under Rule 26(a)(2)(A),
    as opposed to the majority’s speculation
    about strategic motivations. CTS was well
    aware of the existence of each of Excel’s
    four modelers since their work and
    computer models were turned over in
    response to discovery requests in August
    1996. One of the modelers, Eric Evans,
    has even been deposed by CTS. It is quite
    hard to see what Excel could possibly
    have gained strategically through an
    attempt to hide them.
    Finally, let us suppose that there is
    now some controversy regarding the use of
    QuickFlow and SLAEM for modeling in this
    case. Everyone agrees that Valkenburg
    cannot testify about the differences
    between these programs and others that
    might have been used because he is not an
    expert modeler, and so additional
    testimony is required to rebut this
    challenge. The district court found that
    because Excel had failed to disclose the
    four computer modelers earlier (as
    experts; at least two of the modelers
    were disclosed as fact witnesses), it was
    compelled to strike their testimony by
    Fed. R. Civ. P. 37(c)(1). Rule 37 is
    designed to prevent a party from
    springing new expert testimony on an
    opponent at the last minute. The remedy
    of striking testimony is admittedly a
    drastic one, and some circuits have found
    discretion to relax it, Newman v. GHS
    Osteopathic, Inc., 
    60 F.3d 153
    , 156 (3d
    Cir. 1995); Orjias v. Stevenson, 
    31 F.3d 995
    , 1005 (10th Cir. 1994). We, however,
    have held that exclusion is automatic
    unless the sanctioned party proves that
    its violation was either justified or
    harmless. NutraSweet Co. v. X-L Eng’g
    Co., 
    227 F.3d 776
    , 786 (7th Cir. 2000).
    I believe the failure to disclose was
    both justified and harmless. First, since
    the changes in variables, rather than the
    specific modeling program used, appear to
    account for most if not all of the change
    in the size of the capture zone, Excel
    was justified in producing an expert who
    could respond to these criticisms without
    worrying about the more technical aspects
    of its experts’ work. Furthermore, the
    only harm cited by the majority opinion
    is the seven years that have elapsed
    since this case began. But that is a
    misleading time frame. The case was
    stayed for nearly three years while the
    United States and most of the other
    parties negotiated a settlement. Then the
    district court took over thirteen months
    to rule on the motion to strike. The case
    has been pending before this court for
    over a year. Thus, the case was in active
    discovery for just a little under two
    years, hardly a great span of time in a
    complicated environmental cleanup suit.
    The only other harm noted by the district
    court was that CTS might have to hire
    additional computer modelers to testify.
    Presumably, though, CTS must already have
    some modelers on hand who dispute the
    validity of QuickFlow and SLAEM, or else
    its attorneys could not credibly raise a
    challenge to Valkenburg’s reliance on the
    programs. I therefore cannot conclude
    that CTS has been harmed. In summary,
    even if I am wrong about the need for the
    testimony of the computer modelers, I
    would find that their affidavits fit
    within the exception noted by NutraSweet,
    because Excel’s failure to present them
    earlier was both justified and harmless
    to CTS.
    No one should be under any illusions
    about the importance of the difference of
    opinion between the majority and myself.
    The majority thinks that every party who
    wishes to proffer expert testimony has an
    obligation under the discovery rules to
    name as an expert everyone whose
    expertise in any way affects the opinion
    of another expert: my example of Experts
    1 through N above. In my opinion, Rule
    702 expressly permits one expert to rely
    on the informed opinion of other experts.
    An opposing party who wishes to argue
    that the underlying expert’s opinion is
    contestable, in the sense that both
    Daubert and amended Rule 702 use this
    idea, is entitled to produce evidence to
    that effect. That should occur during the
    Daubert/Rule 702 hearing. At that point,
    if the court agrees that it is confronted
    with a situation more like the
    theoretical economist and the
    econometrician than like the doctor and
    the x-ray technician, the court should
    afford the party proffering the evidence
    the opportunity to name Expert 2. That
    system respects the fact that in our
    complex society, all experts rely in
    countless ways on the conclusions of
    other experts, and it structures the
    process for deciding which of those many
    experts must testify at a trial. The
    majority’s rule does not; it proceeds
    from the unwarranted assumptions that
    experts are "hiding behind" the work of
    other experts, that there is no
    obligation on the resisting party to
    introduce so much as a scrap of evidence
    to challenge the secondary expert’s work,
    and that parties must name everyone from
    the hydrogeologist to the weatherman from
    Day 1. Although many might have thought
    that litigation in areas like
    environmental disputes, antitrust, and
    intellectual property could not become
    more unwieldy and expensive than it
    already is, the majority has shown them
    to be wrong. Its rule will hamper
    governmental plaintiffs (like the EPA in
    this very case, which named only a
    hydrogeologist) just as much as private
    plaintiffs, and defendants just as much
    as any plaintiffs. Furthermore, its
    approach is inconsistent with amended
    Rule 702, with the "just, speedy, and
    inexpensive determination of every
    action" command of Fed. R. Civ. P. 1, and
    with a fair balance of obligations on
    both parties.
    I would Reverse the district court’s
    judgment, and I respectfully dissent.
    FOOTNOTE
    /1 The committee’s comments are instructive. It said
    "the rule is designed to broaden the basis for
    expert opinions beyond that current in many
    jurisdictions and to bring the judicial practice
    into line with the practice of the experts them-
    selves when not in court. Thus a physician in his
    own practice bases his diagnosis on information
    from numerous sources and of considerable vari-
    ety, including statements by patients and rela-
    tives, reports and opinions from nurses, techni-
    cians and other doctors, hospital records, and X
    rays." Advisory Committee Notes to Proposed Rule
    703. It is evident that some of the information
    that the Committee considered legitimate as a
    basis for the expert’s testimony is itself the
    product of the expertise of others, such as the
    work of other doctors, or the evidence from x-
    rays. Yet this was not a reason to forbid the
    first expert from testifying. Those who wished to
    challenge the testimony were responsible for
    impeaching the basis for it with their own coun-
    terexpertise.