Abused SeaWall Glitch

I've been in this game for about 4-5 Hours now, and I can't end the game due to this one particular player. While what he did is probably not against the rules, I do think it is particularly "dickish". He made all the other players quit the game due to the fact he wanted to SP Farm, he even said it during the game. He claimed he would only ally end when he had gotten the xp he wanted. I have no problem with this but in this particular map there are no air units and he was able to wall one of his coastal cities so that it was unbreakable.

http://prntscr.com/esllu0

So basically he was unkillable, and he knew this, so he waited out all the other players and made them quit the game. (Keep in mind, I am in the beginner lobby, I just reached Rank 7) Right now I'm currently in game

http://prntscr.com/eslnmx

He's basically saying unless I ally with him he won't end the game unless we hit the 200 turn marker. Well, take this as a rant if you will, but

Player in Question.
http://prntscr.com/eslnsk

The problem is solved. Do not abuse glitches.