I agree with your points entirely.
It’s just hard to believe that there still exist pockets of unsurveilled public access property anymore.
I’m going to make 2 bets here:
1. there was video of the parking lot.
2. that video no longer exists and the theft was an inside job by an employee or one of their buddies.
I’d be willing to give fair odds to one or more of the the following:
1. Camera or DVR was not working. It hasn’t worked in months and the owners probably didn’t even know or wouldn’t pay for repairs.
2. Cheap cameras just barely show you shapes and maybe skin color but no recognizable features.
3. Thief was smart enough to know where the uncovered entrance is.