I've seen this happen a fair bit and dealt with a few cases where the cats were very stressed in the home, and took to taking that stress out on passers by, particularly passing dogs, other cats in the area and children.
If someone owns a cat and is aware that their cat poses a danger to members of the public, they can be held liable. Usually the issue is proving they were aware, but if there are multiple reports made, it can be done.
The only solution is for the cats to be prevented from accessing public places by use of catios/secured gardens/cat runs - once they learn to do this and are successful at it, they will not stop until either severely injured or killed. It is a self reinforcing behaviour:
Fear the approach/passing of stranger through what they consider their territory - attack - stress levels rise - fear increases - stranger leaves their territory - cat is flooded with relief which feels good - behaviour worked = behaviour reinforced.
Even if the percieved threat did not leave the area though, but fought back, as another dog or cat might (or indeed a human) and hurts and scares the cat more - you're adding more aversives to a situation filled with aversives, the cat learns that people/animals in their territory are indeed a huge threat - escalate offensive aggressive behaviour in future.
You'd have to get incredibly lucky to time some sort of unpleasant consequence, that was SO unpleasant the cat wanted never to repeat it, yet not actually injurous, that the cat linked to its own behaviour rather than the presence of others, to fix this.
Fixing the underlying stress/fear that tends to trigger this sort of behaviour is really the way forward, but it's basically impossible in animals allowed to roam.
Anyway, definitely ask for vet bills and make a complaint and encourage others to do so.