Yeah, that was definitely odd. We ended up playing it a bit more later, and while we never stalemated again, it didn't crash. I tried going back in by myself and forcing a stalemate a couple times (one with Sudden Death turned on, and the other with it off again), and it crashed both times still.
EDIT: ...wait, wasn't someone reporting a similar issue over in the Waste thread, when it would crash on a stalemate? I've never had Waste stalemate on me (due to the points adding time all the time), so I don't know if it would do the same for me. I'll try it sometime.
EDIT 2: Went and tried to stalemate waste this morning, to see if it'd do the same thing, but no luck. it didn't crash. So, i dunno.