cbwjm
Legend
You don't need to retcon anything, you can just say "Hey everyone, that was incorrect, we will run it the correct way from now on". No retcon needed, the game keeps on running fine.Correcting it later means one of two things has to happen:
1 - The erroneous action needs to be retconned to its correct version, which potentially invalidates every second of play that happened after it due to the one-thing-leads-to-another effect; or
2 - The erroneous action is allowed to stand in isolation, meaning that your rulings are now inconsistent with themselves (which I think we all agree is bad bad bad).
And so, getting it right the first time becomes important.
Note that characters being antagonistic to each other does not mean the players are being similarly antagonistic. The players might be laughing their hearts out while their characters chop each other to bits.
If I'm playing in a game and I know or find out someone is stealing from me, I'll do something about it in character; and whether the person stealing from me is a PC or an NPC makes no difference whatsoever to what my character does next.
Ditto if I'm the one doing the stealing; if my character's dumb enough or unlucky enough to get caught I-as-player am well aware there's likely to be in-fiction consequences (and would, in all fairness, be annoyed were there not; if that lack of repercussions was based solely on the rationale that my character is a PC).
As both DM and player, I don't believe in "PC glow".
Sure in some groups players might be laughing, but if I ask the player of the thief to stop stealing from my PC and they don't then I'm done with the game, because, as I said I don't like games where the players are antagonistic to each other.