ptab should raise its own ground of unpatentability only in rare circumstances

On July 6, 2020, the Precedential Opinion Panel (POP) issued a decision holding that the Board should not raise its own ground of unpatentability against proposed substitute claims in deciding a motion to amend.  Hunting Titan, Inc. v. DynaEnergetics Europe GmbH, IPR2018-00600 (P.T.A.B. July 6, 2020) (Paper 67).  According to the POP, inter partes reviews are adversarial proceedings and the Board relies on the parties to bring the most relevant arguments and evidence to its attention.  The Board should raise a ground of unpatentability that a petitioner did not advance, or insufficiently developed, only in the rare circumstances where the adversarial process fails.