A recent opinion of the US Court of Appeals for the Seventh Circuit, Kopplin v. Wisconsin Central Limited, http://media.ca7.uscourts.gov/cgi-bin/rssExec.pl?Submit=Display&Path=Y2019/D02-01/C:17-3602:J:Sykes:aut:T:fnOp:N:2286594:S:0, is an excellent reminder that a case can fail without a well-chosen and properly prepared expert witness.
Here’s a timely reminder that Federal Rule of Evidence 702 (the basis of the Supreme Court’s famous Daubert decision) imposes a four-part test. For expert opinion testimony to be admissible, the fact that the expert has “scientific, technical, or other specialized knowledge [that] will help the trier of fact to understand the evidence or to determine a fact in issue” [Fed. R. Evid. 702(a)] is necessary, but not sufficient.