We keep writing about how hard it is to win a motion to strike in D. Del., which is generally true. That said, it's still possible to get late-disclosed theories and evidence excluded, especially when there's no good explanation for the delay.
Yesterday afternoon, one plaintiff learned that lesson the hard way. As often happens, the plaintiff argued that the defendant's expert raised new opinions on motivation-to-combine in his reply report.
But instead of moving to strike (or seeking leave to submit a sur-rebuttal report, or dealing with the issue during expert depositions...), the plaintiff simply waited until summary judgment briefing. There, it submitted a rebuttal declaration from its own expert in support of its answering brief on invalidity. …