Steam will only sync files after the game exits, whether it crashes or not. Any problems you have, take them up with Steam support. Odds are, they'll give you the same answer. Your game crashed for one reason or another, and that's all that happened. Steam was not involved.
I say this because, after using steam for probably 4 years, I've never had steam exit any game for me. After checking error logs, I've confirmed every game crash to be the result of some kind of computer or compatibility fault.
If you think my name is silly, you should call me either Rob or LaughingThesaurus.
No need for being strictly formal on a message board, right?