He committed no crime period.
Unwanted touching with pain is assault....these circumstances make it a b.s. assault not worth grown ups wasting their time and life energy over.
But by the letter of the law it is an assault (simple battery I think they call it in that jurisdiction)
As a police officer i would have tried very hard to c9nvince both parties to grow up and get over it.....not every disagreement or bad behavior requires govt intervention.