Yeah, it obviously varies by location but my garage door is open a lot and I am not always out there so it really depends. Maybe I pulled the smoker out, midway mowing the yard, ran in to grab a beer and got sidetracked, etc. I have 5 bikes (3 costs over OP value), tools, and tv and I don't see it as that big a deal. Pretty friendly subdivision so if I am home I don't have a problem with it being open. I did however put a timer on my garage to shut it if I accidentally leave it open at night. Guessing the OP situation is nothing like this which sucks.

I know it's a roommate and not a friend per se, but if I was in his shoes I would just appreciate they offered anything to help. Mistakes and shit happes