The court did however provide guidance on how counsel can appropriately help an expert witness prepare his/her report. Specifically, the court noted that
[i]n most cases, expert witnesses are not attorneys, and they may not apprehend the required components of a report set forth in Rule 26(a)(2)(B). The retaining attorney certainly may explain the rule's requirements and coach the expert to be sure the report touches all the bases. That is a far cry, however, from abject ghostwriting, which is not allowed under any circumstances.
In assessing the expert's role in Numatics v. Balluff and Barnum the court's opinion was informed by both the lack of time and effort spent on the engagement by the expert and the striking similarity between the text of the expert's report and that of defense counsel's contentions.
Specifically, the court found that the expert had spent a total of "less than 30 hours developing his opinions about the case, nearly half of which was spent at or traveling to the law office of Balluff's attorneys."
With regard to the actual text of the expert's report, the court found that sections were "copied nearly verbatim from [the defendant's] invalidity contentions" submitted by counsel:
Section H of the report…is nearly indistinguishable from Balluff's third supplemental invalidity contentions…The pictures, charts, and diagrams are the same. The Citations are the identical. The prose is indistinguishable down to the punctuation, leading to only one possible conclusion: the report was ghost-written by Balluff's attorneys as a legal brief disguised (thinly) as an expert disclosure.
Although plaintiffs had only sought exclusion for specific sections of the expert's report, the court excluded the expert from the case completely, characterizing him as "nothing more than a highly qualified puppet." Citing Rule 702, the court pointed to its role as a gatekeeper noting that
[e]xpert witnesses are allowed to testify based on information furnished by others because they have technical expertise in a given field that 'will help the trier of fact to understand the evidence.' An expert who is merely a party's lawyer's avatar contributes nothing useful to the decisional process.
This decision reinforces the importance of adhering to Rule 26 but also to maintaining clear boundaries between expert opinion and legal argument. An expert that is viewed by the trier of fact as nothing more than a mouth-piece for counsel is essentially of no value. The power of using an expert witness effectively comes from the expert's objectivity, both in appearance and substance. Counsel should be cautious of becoming too involved in the drafting of its expert's report. Doing so may be disastrous for the case if it results in the expert losing credibility or being formally excluded.