Yes, and how can we find out what classes they were playing? With replays. Isn't this common sense? They're also more likely to post what they were doing when their game crashed, if a thread is readily available for it.
The crashes with Geoset error are memory crashes, that's why the game doesn't crash for everyone at once. One person crashes at a time, usually the player with the least RAM available will drop first (everyone else keeps playing). If it was a more conventional critical error, everyone would crash at the same time. I highly doubt the problem starts when the player crashes.
I've lost interest now though. You can hunt the information on your own.