In Burgess v. United States, No. 15-12045 (Nov. 6, 2017) (Rosenbaum, Julie Carnes, Schlesinger), the Court held that a district court is not permitted to sua sponte invoke a 2255-waiver provision in a plea agreement to dismiss a 2255 motion where the government fails to raise that defense in its response. The court limited its holding to collateral-waiver provisions.
Judge Carnes concurred, agreeing with the majority's conclusion, but emphasizing the narrowness of the opinion. She pointed out that nothing prevents a district court from sua sponte directing the parties to address the waiver issue before the government responds. And the government may seek to amend its response to belatedly add a waiver defense, subject to the court's discretion.