Looks like work of the Flight Termination System. Something measurable had to go very wrong.
While the telemetry was still going, you could see Ship engines going out one by one. Earlier when there was video there was what looked like flames visible inside one of the flap hinges, definitely shouldn't be there on ascent. Presumably something failed internally and caused the Ship to shut down before reaching target trajectory, at which point either FTS or the failure itself caused it to blow up, as seen on the Insta reel.
On the NSF youtube channel they pointed out that at some point the methane indicator started decreasing much faster than the LOX indicator, which points to some sort of leak. It would explain why the engines started to shut down.
> Something measurable had to go very wrong
Or slightly wrong. An FTS is programmed to be conservative. Particularly on unmanned flights. Doubly particularly on reëntry. Triply so on experiments bits.
Depends on the programmers I guess ¯\_(ツ)_/¯
All of the exception handling was spent on the try/catch of the booster.
It wasn't FTS, it just blew up: https://x.com/SpaceX/status/1880033318936199643
That doesn't negate FTS.
Imo if SpaceX thought it was possibly FTS they wouldn't say RUD. They still had telemetry for multiple seconds as it pitched wildly and engines failed, if FTS didn't trigger then it probably didn't at all.
Yeah I thought about that some more and at that altitude and speed the FTS is usually already deactivated.