How much stuff is there to fuck with in a standard, untampered-with pager? Seems unlikely this was pure cyber (and some novel battery hack). And if you need supply chain interception to carry out the attack in the first place, why wouldn't you insert explosives? There's a history of these kinds of attacks.

Yeah, agreed. Also agreeing with the sibling posters that the videos that emerge look nothing like batteries catching fire but rather like actual detonations. Nothing an untampered pager should be able to do.