The Latecomers

Dear S.B.A,
Our coworker/relief came up to the register at 4:36pm. I still had to put up my overstock so I didn't clock out until 4:42. Before I left my post, I said to our coworker, in front of everybody,
"You might want to think about coming to work on time. You're late, like, everyday. It's crazy! I'm just saying..."
The guy that I was ringing up sounded like he said that I shouldn't do that. But he actually said that our coworker shouldn't do that. Meaning he agreed with me that our coworker is some sort of idiot that should be able to make it to work on time.
I told our other coworker what I had said to the latecomer and she told me the person I should be complaining to was our boss. Because she doesn't want to see me get accused of harassment. So I told our boss and he acknowledged my complaint and told me to come in ten minutes late. And because I'm crazy and paranoid, I double-checked to make sure he wasn't just messing with me.
When are you coming back?