What state was he in? I know some people who were convicted for DWI in Texas and California. Had to be in probation for 2 years, do some community service and shit. He graduated, and changed his status from F1 to H1 while he was on probation for DWI.

So, I don't see it much of a problem, as long as you hire a good lawyer, and don't start following Paris Hilton's steps. So your friend should be cool.