I always kept my passenger door locked and wrapped the seatbelt thru the armrest/door pull then latched the seat belt. I had to do some pulling to get it latched, but I felt a lot more secure knowing that someone could not get the door open. I also would do the same to the driver side door when I went to sleep.
My German Shepherd would have found that stunt amusing, that guy wouldna had a chance to get the gun pointed at anything with a German Shepherd hanging off his throat.