You respond to force with force appropriate to stop whatever it is that is going on AND NO MORE. If the force being used against you is someone calling you names, move away if it annoys you, but if you knock the person down you are over-reacting.

If someone aims a blow at you, you have every right to block that blow and to leave the area if you safely can. If someone tries to knife you, you have the right to do whatever is needful so that you won't be stabbed.

In short, the response to force MUST be proportional to the force being used against you or against someone you are protecting.

Pulling the woman back from the car would have been appropriate force. Dumping her to the ground and doing whatever was done is not and the man should have been arrested.

(From a personal viewpoint: the man would have left on a stretcher -- no functional gonads and at least one broken kneecap. I take self-defense seriously.)