We last wrote about Mitchell v. JCG Industries, No. 13-2115 (7th Cir. Mar. 18, 2014), in mid-March, when one judge on the panel (all suspected Judge Posner) confirmed his “intuition” that plaintiffs in a donning-and-doffing case overstated the time that it took to don certain articles of protective clothing by conducting an experiment in his chambers, recording and timing his clerks as they put on the same articles that the plaintiffs donned daily at their employer’s poultry-processing plant.

Yesterday the Seventh Circuit denied rehearing en banc in the case by a 6-4 vote. Judge Williams wrote an opinion dissenting from the denial, joined by Chief Judge Wood (who dissented from the panel decision too) and Judges Rovner and Hamilton. Judge Posner wrote an opinion concurring in the denial–a move “virtually unheard of”–where he admitted that he and his clerks conducted the experiment (freeing Judge Kanne from any untoward suspicion) and where he further defended the experiment, denying that it was “evidence” or “appellate factfinding.”

Apparently the petitioners were not too happy with Judge Posner’s experiment. Judge Posner explains: “The petition denounces the experiment conducted by ‘unidentified members of the judiciary’ (these villains are my law clerks and I), which it states violates due process and the Federal Rules of Civil Procedure.”

Judge Posner fired back at the petitioners, accusing them of having now conceded that donning the protective gear did not take 15 minutes, by virtue of their new arguments, not pursued previously on appeal after having forfeited them below, that the 15 minutes included other acts, such as storing the clothing and washing up. “Now they concede (maybe without realizing this) that no, those acts alone don’t add up to 10 to 15 minutes. It’s those acts plus additional ones that do.”

Judge Posner also was “puzzled” by the dissent’s belief that all this was an issue of fact for a jury. “My puzzle is: how is such a fact to be determined by a jury?” If one worker testifies that it takes 10 to 15 minutes to don and doff, and if another testifies that it is 2 minutes, “[h]ow is a jury to decide between them?”

“[T]he most accurate way to resolve the dispute would be, on the model of the criticized experiment by court staff, to videotape workers doffing and donning.” That model could be flawed, Judge Posner recognized, if the plaintiffs dawdle and if workers aligned with management rush. Left unsaid, of course, is the implication that he and his clerks could slake his curiosity in an unbiased way.

Judge Posner leaves his detractors with the unapologetic thought that all this “illustrates the important point that determining facts in litigation can be devilishly difficult if one thinks accuracy important.”