I think we can all debate whether or not the driver actually ran over the cops foot or not, but I don't think that's ultimately the real issue here. Yes this will have an impact on the severity of his punishment but the real issue here is that he disobeyed a clear instruction from the officer.
You can clearly see in the video that the cop asked him repeatedly to stop and the driver kept ignoring him. You just simply can't disobey an officer and if you do then the police officer may feel that his safety and others are in jeopardy specially when the other party is behind the wheel of a motor vehicle. It then ultimately gives him the right to use any force necessary to get the situation under control.
Everything else that happened afterwards - punching the window, smashing the door open, forcefully removing the driver & slamming him to the ground - will be seen as justified by the court and the officers supervisors.
No matter how minor or major a situation is you simply have to obey an officer.