I profoundly disagree with the elderly women harassing users of this clinic, but that doesn't alter the fact that the violent intervention by this young man is counterproductive and has been misrepresented by the press in a way that will work against women. It could be chalked up as another instance of a woman acting violently, when it's not. It makes the pro-choice movement look bad, and gives the media the opportunity to smear everyone involved ('both sides behave equally badly, etc.)
I also suspect that this person is using politics as an excuse for violent behaviour, in this case bravely attacking a group of people who aren't much of a physical threat. Apologies as I've said this before, but when I was at uni I was a bit of an animal rights activist, and I noticed that some young men seemed to be in it purely because it gave them an excuse for violence and bullying others. They exuded self righteousness and had a good excuse to bully other people on behalf of animals (even though as young white middle class males they suffered no actual discrimination themselves).
This young activist has probably done nothing to support women needing to use the clinic, but may have done a lot of harm by attacking these old women. And I don't condone that behaviour just because I disagree with the old women.