I had this done to me once at a tournament. I fixed my mistake and he A.2'd his mistake, even though we hadn't moved to the next phase. He pulled out the ASOP and made his point. I lost the game on the 2nd turn but I played all 8 turns, telling him he was free to resign at any time. The game lasted until 0800 the next morning, a full 15 hours. I read the ASOP from top to bottom for EVERY piece moved EVERY HEX. He would move a unit 1 hex, I would tell him to hold, and then read the whole ASOP before telling him he could move to the next hex. Then do it all over again. My turns took hours. His turns took even more.
Why you ask? Because fuck him, that's why.
I have some love for that approach - "I don't get mad. I get even..."
Yet hard to tell, how I would react if this happened to me.
In general, I always play friendly, no matter if it is a normal game or a tournament. I am there for the fun, so if a misunderstood setup-area screwed up the game, I'd tell my opponent before the game starts and have him fix it. I am not anal about the ASOP if my opponent confuses the order of repairing and deployment, I'd also allow him a repair attempt if he noticed that he forgot so during his next fire phase.
If I do get sharking in return such as described, then I'd turn sour. If my opponent has a reputation for sharking or being overly ambitious in the line that 'the win' is more important than 'the game', I would weigh my personal desire to have fun against the "I don't get mad. I get even..."-approach.
If my personal desire for fun wins, I'd end the game, concede, and express to the opponent what I think of his handling. I'd also not hesitate to let others hear the story and the name. But wasting more hours on that guy? Meh.
If the darker side wins, I can sure could make his 'win' a pain. Under certain circumstances, some sort of fanatic streak might be kindled in me. The latter way is less likely, because I would have to sacrifice some of my fun to kill his, which is - as we know - not really worth it.
In any case, I would not play that guy in the future.
von Marwitz