Come oooonnnnnn... Obligatory disclaimer for everyone else: IANYL. Mostly, because armchair lawyering on the internet is the worst. That said – sure, estoppel

Come oooonnnnnn... Obligatory disclaimer for everyone else: IANYL. Mostly, because armchair lawyering on the internet is the worst. That said – sure, estoppel is absolutely an important part of the judicial/common law canon. It's also often a last ditch effort when multiple other theories of the case fall through. In fact, before estoppel was mentioned, I thought OP was going for unclean hands, which might be truly the last hail Mary, and absent much more, estoppel is equally far down that list. Not sure which is worse: Dunning-Kruger here or if OP is actually in a position where (s)he should know better. All the Wikipedia and common law cites make me thing maybe a foreign attorney best case scenario. tl;dr: Extremely broad but rarely used as such legal principle is cited as reason Apple is legally DOOMED! From that misleading jumping off point, OP gleefully takes the giant leap to asserting that an otherwise novel and highly disputed antitrust case involving the App Store et al. is open and shut when it very much isn't.