Unless I see someone stealing, I keep my mouth shut and do my job. Thankfully, I have yet to see anyone stealing from the company.
Look at it this way..you are probably part time right? You're there tops, 5hours (on a usual day) - just relax. You're getting paid x.xx whatever an hour weather he takes that extra 10 minutes or not. The person could have health issues, you don't know. If you want a brown noser (no pun intended) job, go to wal-mart or some other retail job and kiss ass like that till you work your way up to the assistant manager posistion and brag that you bring home 30k a year.