It's illegal for her to not pay you for that hour worked, no matter how worthless you were during that time. If she disputes it, you can contact the Wage & Hour Division of the Department of Labor.

Of course, the side effect is she is probably waiting for the next time you show up 10 seconds late so she can just fire your ass. Legitimately.

I had somewhat of a similar experience when I was in college.

I worked at a restaurant with one cash register used by all employees from open until close. Suddenly the register started being short on a regular basis. We are talking by about $20 on average. So the owner starts docking everyone who worked that day for a portion of what was missing.

The problem I had with this was that I had never stolen money and in all my years in retail (worked at a pharmacy prior to this), had never had problems with giving incorrect change back. It was obvious to me someone was stealing and it was coming out of my pocket.

I'm not sure what legal recourse I had because I got so pissed at my boss that I decided I would just find other ways to get the money back. In hindsight though, I wish I had looked into it based on principles. The guy was a dickhead.

I have a related question: I am a salaried employee - no overtime - and in a document of "company rules" it states that if we arrive late without notifying anyone then we can be docked 1/2 day's pay even if we didn't miss 1/2 day of work. Is this legal. I don't remember reading it in the contract I signed...