Micro-Aggression?

OK, so I'm starting to get what the other people in this department are saying when talking about the guy who's training me.  I think.  Today he sort-of ripped a paper out of my hands, and I think I got a paper cut.  Is it micro-aggression?  Nervousness?  I think it's an accident, and throughout it all (and the whole day) he was kind and docile.  But there are other behaviors that tell you about a person, and ... yeah, I didn't need that, let's just say.