At the least, till the bug is fixed; maybe ask the *other* player to resign. If I had lost a game, but got an in-game message, saying that the game would not officially end, I'd be happy to resign. I already know I lost the game, right? :-)
My guess is that most other players will respond the same way. There are a few bad apples. But most of us are reasonably good sports. . . at least, based on my own experiences in the game.