It wasn't an obvious bang , call 911! , weewooweewoo

It was slower. First I check the tiny kid. He said he was fine but it was a hard hit. I send bully to admins. I had tiny kid sit with ice. We called his parent to say he was hit. Then swelling formed a minute after I got off the phone. Meanwhile bullykid is scolded (by my coworker) and picked up by his parents at regular school release time like it's no biggie. Tiny kid has a hematoma by the time his parents arrive. They drive to the ER. Next day the family informs us of a lie. They drag it on for a few weeks. About 2 months after the incident my admins finally cave and bar the bully from school. It wasn't his first incident.