Bill: I gather[1] that game records are kept for finished games, and that some people try to cheat by marking stones dead at the scoring phase. If they tried to do that to me, I would let them, and then appeal the result. The game record is good evidence. ;-)
Here black could be marked dead by the scoring facility until the area is closed off (black is alive unconditionally here) However if the opponent would continue to mark alive groups dead then I would end up reporting the incident to an admin
penguin: The admins are not interested in refereeing games.
Bill: I still appeal. :-) If people really are trying to cheat in this way, the message will get through.
Zarlan: I'd be stubborn and correct the life/death status ...or if I get tired of that, I'd just leave.
I would not allow an incorrect result. Not getting the game finished is very annoying even if it's a free game (has happened to me), but well... it's just one game and the only real lasting annoyance is the fact that I won't be able to access the game-record through my game list.
[1] Bill wrote originally "from this note", referring to text which is now on Escaping, under the headline "My opponent escaped, what can I do?"