My best guess is that it works kinda like the GBA RNG. GBA games pre-roll RNG values when a chapter is loaded, but it doesn't save the exact values, only the general range (high and low). If there's a situation where you get crit every time you repeat the same actions, you can eventually get the crit to fail through infinite resetting. I might be remembering certain things wrong, but that's how it works to my understanding.
Anyway, I think that's kinda what Mila's Turnwheel does. Newer FEs don't do pre-rolls anymore, but Turnwheel activation will save the general range of the RNG you got.