If the arrest for obstructing wasn't merited, the right way to handle that is to hire a lawyer. Fleeing the scene in a vehicle is never the right approach in America (or frankly anywhere), it endangers the public generally not to mention your own life in particular.

In either case, it shouldn't matter to this case. The man should be put on trial not to decide if ICE's mission is legitimate nor to decide if she was guilty of obstruction or fleeing, but rather for murder. The question of whether he, in that moment, genuinely believed there was a lethal threat to his life is what should decide this case.