Obviously handing the ball to Washington wasn't just a friendly gesture of goodwill, but it was a cheeky mind game sort of thing, not a threat or anything that would warrant having the ball tossed at his head from 5 feet away. You see guys hand the ball to opponents all the time. The opponent usually acts like the ball is radioactive and everyone moves on. And I would absolutely go after someone who threw a ball at my head, but Mathis should have gotten in his face and started jawing rather than anything physical. Easy T on Washington (not that it mattered at that point) if he retaliates verbally.
We are Rutgers fans, we should be experts in the field of when it's appropriate to throw a basketball at someone's head and the appropriate response.