Your choice is to do nothing. It is too late.
I had this happen to me this season and it seemed like everything went into slow motion. It was one of those nights where there wasn't any other games being played and the two teams didn't like each other. The coaches had actually almost got in a fist fight last summer. The coaches didn't want to play each other, but the ADs said the games would be played. When I made the call, even the officials in the crowd (on the endline) paused for a second. I knew something wasn't right because I had just told the kid it was a spot throw in.
BTW, I have the rematch at the other school this coming Thursday. This assigner has really been good to me considering I'm new. Maybe I can ref a little.