Incident on the playground

When I picked up Rhys from kindergarten today, his teacher told me there was an "incident on the playground" which left him with a scratched face. I didn't think much of it; he must've fallen. He trips easily. But after half an hour I thought it looked suspiciously like scratches from a hand. 

Sure enough, when I asked him, he said one of his classmates did it. But he couldn't really remember a lot of the incident (part of his delayment issues come from lack of memory and ability to explain or speak properly), so I don't know what happened. Something about the girl being tagged or not being tagged while they were playing on the playground. (it was just the two of them, plus another boy, during free play. The rest of the class was inside the room, which is steps from the playground. So no adult witnessed this either.)


Sadly, this girl has been rough with him a few times.  I'm not too sure what to do about it. I want to mention it to the girl's parents, but I also don't want to come out as if Rhys was completely innocent in it either, since I don't know if he was.  Did he say something to her? Was he being mean? Did he shove her or retaliate? Not that that excuses her scratching in any way, but it does make it less of a 'your girl is beating up my boy' and more of a 'our children don't get along' thing.  I've never had to deal with this in the other kids.  

It makes me sad because he is a sweetheart. It also makes me frustrated that it is shrugged off by the teacher.  He already talks about how one girl (a different one than this one) is mean to him and always shoving him!  And I don't understand why.  Is he doing something? What causes them to shove him? (the two girls seem to like to do this) My poor boy, who can't explain himself very well.