Larry is in police custody for a suspected robbery. There is some evidence that he stole a watch out of a locker where he worked.
"What happened at the factory, Larry?" Chief Brossard asked.
"I came to work at 5:00 AM as I always do. We worked until noon when we ate lunch, which lasted an hour. I-"
"What do you do at work?"
"I cut metal slabs."
"How long does that take?"
"About one minute per strip. They're for motor vehicles. Anyway, after lunch, I had exactly 179 strips to make. Three hours later, I came into the locker room to change and go home when I saw a locker broken into. Some people came in and accused me of stealing someone's watch. I didn't have time to steal it because when I got off at 3:59 other people would have seen me as an entire shift gets off, and a minute to get there and break into the locker isn't enough time."
With fingerprint evidence, Chief Brossard's suspicion was true that Larry stole the watch. How did he do it?