I'm wondering what people tend to do when they spot a mistake has been made. Do you attempt to rewind to the point where the mistake was made, or do you say that if a mistake isn't spotted then it's fair game?
For example, in our last melee game we were going through the Challenge phase and noticed that player A was attacking player B whilst he was supporting that player via the titles, and therefore shouldn't have attacked him. We tried to 'rewind' to the start of that player's challenge phase to correct the oversight. But it occurs to me that this isn't without it's own problems. For example, player B now knows that player A had the intent to challenge him and may be more inclined to dish out some retribution than might otherwise have been the case. Or perhaps some events have been played so now everybody knows what's in somebody's hand, etc.
So I'm thinking it might be easier to just say "what is done, is done" and carry on after acknowledging the mistake.
How do others address this situation?