No one disputes that Oklahoma’s Joe Mixon as someone says in the background of the 911 call says “knocked her ass out”.
What is in dispute is what led to the KO. Mixon’s attorney says it was self-defense and he was attacked first. Stephen A. Smith and Whoopi Goldberg might find that acceptable, others may not.
You can listen to the 911 call above via NewsOK that describes the scene after she was hit and Mixon left the scene. Most important part is the caller says they have video cameras all over the restaurant, so eventually what actually happened will come out.