In separate arguments at the Dec. 5 hearing, defense counsel asked Judge Redford to bar plaintiffs from using patterns of governmental inaction as the basis for a takings claim and to exclude or limit reliance on simulations by Dr. David Williams.

Nathan Frishkorn told the court that Michigan jurisprudence requires affirmative government acts for inverse‑condemnation claims and that courts have not treated pure inaction as the constitutional wrong plaintiffs allege. Frishkorn distinguished deliberate concealment (which he said could be relevant) from mere nondisclosure or failure to act, which defense characterized as tort/negligence territory rather than takings law.

Plaintiffs’ class counsel Jason Thompson responded that relevance under Rule 401 requires the factfinder to see context; plaintiffs said patterns of omissions and subsequent affirmative decisions could be probative when evaluated with other evidence. Judge Redford probed whether a collection of failures to act could inform intent behind an eventual affirmative act.

On modeling, defense counsel argued that Dr. Williams used incorrect inputs in at least three respects (including dimensions related to spillway gates), which defendants said undercuts any claim of 'virtual identity' between model inputs and the conditions of May 20, 2020; defense urged preclusion or limitation of the model’s probative value. Plaintiffs and defense disputed whether hydrologic modeling uses architectural dimensions directly or effective hydraulic widths and whether Lemons (a recent Michigan Supreme Court decision on modeling) permits expert modeling when perfect replication is impossible.

Judge Redford allowed argument but did not rule from the bench. He encouraged counsel to prepare for cross‑examination and to identify which experts would present modeling inputs at trial. He again indicated he would issue a written order next week.