That shows the reaction of passersby to a person cutting locks. The person actually owns the bike-- a fact that is not apparent to the passersby, but which nevertheless would have some effect on the attempt to break a lock. The bike owner cutting his own lock is in no fear of getting caught. The bike thief in the same situation is always at risk of having the true owner return to catch him in the act. Don't mistake the reactions of the passersby with what the thief is thinking as he's spending 10 or more minutes with a power tool cutting a lock on a bike he doesn't own.

Is it possible that an experienced thief could pull this off (especially if the thief has cased out the bike over a period of days or weeks)? Yes. Is it likely that a thief would risk getting caught by the true owner when their are other bikes, locked only with a cable lock, nearby? Not in my opinion.