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The Temptation to Depose Every Expert

Emily Jo Kirk


  • Attorneys should cautiously consider deposing an expert witness due to Rule 26(a)(2)(B) implications.
  • Deposing may allow experts to expand beyond their reports, potentially introducing new information that could be permissible in court despite initial presumptions of exclusion under Rule 37(c)(1).
  • Tactical considerations play a significant role; not deposing an adverse expert might leave them less prepared for cross-examination at trial, providing a strategic advantage.
  • If proceeding with a deposition, attorneys must be precise and cautious in their questioning to avoid inadvertently inviting testimony that could bypass Rule 37(c)(1)'s exclusions.
The Temptation to Depose Every Expert
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In "The Temptation to Depose Every Expert," author Gregory P. Joseph discusses the fundamental issues that every attorney should consider before automatically succumbing to the temptation to depose experts.

Under Rule 26(a)(2)(B), expert opinions and exhibits that are not promptly disclosed are commonly excluded from consideration.  Given this, the author suggests that attorneys should think long and hard about whether taking an expert's deposition opens the door to allowing the expert to expand upon what is memorialized in the expert report. Many times, if an expert expands upon or offers different opinions, data or exhibits, the court may consider it appropriately submitted. Thus, Joseph offers that attorneys should consider four lessons before deciding to depose an expert witness.

First, attorneys must consider whether they may well be better off not deposing an adverse expert. The expert has already submitted the report and it must set forth all of the facts and opinions the expert plans to testify to. If new facts or opinions are offered outside of discovery, those new items are presumptively excluded under Rule 37(c)(1). 

Second, attorneys should weigh tactical considerations. Deposing an expert will leave him or her better prepared to withstand cross-examination at trial. If no deposition takes place, the opposing attorney will be more of an unknown quantity to the expert which can be advantageous.

Third, since the 2010 amendments to Rule 26(a), there is less to ask about in an expert deposition. Rule 26(a)(2)(B)(ii) was amended to eliminate the phrase "data or other information" and substitutes "the facts or data or other information considered by the witness in forming [the opinions]."  According to the committee note, this amendment "is intended to alter the outcome in cases that have relied on the 1993 formulation in requiring disclosure of all attorney-expert communications and draft reports."  This amendment, along with Rule 26(b)(4)(C), provides expert reports and communications between the expert and counsel with work-product protection, except to the extent the communications:

  • relate to compensation for the expert's study or testimony;
  • identify facts or data that the party's attorney provided to the expert and that the expert considered in forming the opinions to be expressed; or
  • identify assumptions that the party's attorney provided to the expert and that the expert relied on in forming the opinions to be expressed. 

Given the interpretations that have been given to these exceptions, an attorney is only likely to get identification of facts and assumptions, and the attorney should already have what he or she needs in that respect, and perhaps all that can be gathered, in the report itself.

Fourth, if an attorney decides to go forward with a deposition, he or she must be careful with what is asked.  An attorney never wants to open to the door to inadvertently asking for testimony that is otherwise precluded by Rule 37(c)(1).  Never should an attorney ask a traditional catchall question like:  "Do you have any other opinions as to this case that we haven't discussed?" 

If an attorney opts for an expert deposition, the attorney should do his or her best to instruct the witness to answer only those questions being asked and ensure the witness understands that the questions and answers are limited to opinions or theories discussed in the expert report only.  If an expert wanders from those opinions or theories, the attorney taking the deposition must object and do whatever he or she can to limit the testimony if it is in the client's interest to do so. 

Considering all of these issues, Joseph states that the answer to the question of whether an attorney really wants to depose an expert is often "no."  But, there are also risks of not deposing the expert. For instance, the expert may testify to issues at trial that the attorney does not know or expect. The attorney may be less comfortable confronting the expert for the first time at trial. The attorney may also be uncomfortable about a Daubert motion without a deposition. But, by not deposing, the attorney will not have opened the door to additional testimony through the deposition testimony, will not have signaled elements of the cross-examination or the weaknesses in the expert's analysis making it vulnerable to a Daubert attack, and will not have left a sterling cross-examination in the deposition room while allowing the expert to arm himself or herself with a series of plausible explanations that undercut the progress that may have been made during the deposition. 

Even without a deposition, Joseph notes that expert discovery can still be taken. It is well settled that an opposing party can be served with a Rule 34 document request and adverse experts with Rule 45 subpoenas to obtain unprotected expert material. If an attorney goes this route, though, he or she must be prepared for the same types of discovery requests to be served regarding his or her own experts and every effort must be made to ensure experts will be able to comply.