Maybe Deja vu is when someone reloaded a save
Actually this would be a neat mechanic in-game: everyone around you nopes the fuck out at the sight of you, especially if you killed them previously.
They don't know and they don't understand, but things are very firmly Not Ok.
Partly the cost of failure, possibly a strategic tool.
It happens when they change something
Nah, it's just an async function call catching up.
i miss r/outside...
Maybe you died and the game automatically went back to the last autosave.
https://en.m.wikipedia.org/wiki/Simulation_hypothesis
Maybe
NPC don't even run after you single handly kill half an army, tank insnane amounts of damage, heal massive wounds by speed eating bread, or walk around in the armor of their former unbeatable boss.