"Was this a matter of police use of excessive force or an act of overreaction?"
No and no.
He could have tazed her I guess, but with all the people standing around who knows what may have happened had he reached for a tazer. It looks like the officer was alone, and there were lots of bystanders. Although they were just watching it could have morphed into a mob situation w/serious harm or death coming to the officer. Having been in situations where there are lots of people and there is chaos (ER- sometimes we'd get carloads of people storming the ER bringing in someone who's been shot), things can get out of control quickly, and you must gain the upper hand by any means necessary. I am speaking from experience.
You can tell those girls had absolutely no home training to be jumping up in the officers face, grabbing him in the first place. I'd have gotten my tail beat at home for such behaviour.