Welp, I did the good Aggie engineer thing and actually, ya know, researched this myself.
The thing is, when something controversial like this goes down, it will be scrutinized 100% BY THE BOOK. So it should be pretty cut and dried. And honestly, it is, partly.
Per 2024 official 2024 NCAA Football Rules, there is one and only mention of the time frame of when a call can be reversed. Rule 5, Art 2, Sec 9 is the image. So the "can't change the call after announcement" is folklore. They CAN change the initial ruling at any time up to the next snap, period. That's the easy part.
So, the sticky part. And what comes with a bit of interpretation. The "reviewable" angle. A PI is not reviewable. A review, aka, Instant replay process, is an actual process initiated in only two ways. (Rule 12, Art 5, Sec 1) By a head coach calling for it, and by refs or replay officials seeing a few things they can call for (too many men, egregious targeting, etc).
During the game, the Jumbotron kept showing the non PI slowmo and the refs could absolutely see it was a bad call while the field was getting trashed. It gave them time to "discuss" (very important, that term) and IMO, they made a business decision and reversed the call.
So, to sum it all up. Refs CAN change a call all the way up the next play. A formal review was NOT initiated by either coach or replay official. tu trash fans did tu trash fan things and delayed the game while blasting the obvious blown call the whole time to the entire stadium. Refs "had a discussion" and decided to reverse and after poring over the rules myself for longer than I want to admit, everything that happened from the ref side was by the book and legal. If highly unusual.
Obviously the situation created by the tu fans is worthy of pitchforks itself and created a horrible precedent, but damn me if it did not work on the refs and created a weird one a million shot that actually (IMHO) actually overturned a ruling that 99.999% of schools would never get…..but somehow still be within bounds of the rules.
Conclusion: Man, I hate those puke orange turds so f'ing hard.