When I go into a room I turn on the light. There had to be a light on for the person to see anything. But I can see why you shoot first and try to think later.
So now we are at this scenario:
A father who is unaware that his daughter even has a boyfriend hears noise in his daughters room at 4 AM. He opens the door and turns on the light. A young man unknown to this father is standing naked on his daughter's bed. A reasonable reaction is to treat this stranger in this circumstance as a threat and deal with it accordingly. He attacks the male in defense of his home and daughter. I fail to see what he did wrong. Ask questions? Sure, after the threat is eliminated.
My original statement STILL stands.