Went back and read the gun comments. Good opinions and solid advice. Weapons should only be brought into the conversation when there is a threat to life and limb and it is coming. In this situation they were unable to break the glass and had the owner not opened the door (or left it unlocked) they would not have had access to him. Correct me if I am wrong.
In that case showing a weapon would be silly esp with a family in the vehicle. Who the F knows where the actual police were in this situation but he should have in the best case scenario waited it out. When the window breaks unfortunately he has a right to defend himself. He had options. Foward and Reverse. I know which one I would have used but that's just me. The car as a weapon is a safer bet than showing a handgun IMHO. Either way, I would have moved my vehicle to maintain a safe distance until the gendarmes arrived. Now picture his car, wife yelling at the guy and into the cell phone kid screaming and crying. Tough call.
I understand 11 people of the bike group have been arrested and charged with serious crimes = jail time. That sounds appropriate.
But my last observation repeated. WHERE WERE THE F'N COPS?