It depends whether I was a serving police officer or not.
I think you know the answer to your question. But even then, natural instinct may need to be tempered by the risks/odds involved.
In this case it WAS a serving officer AND it wasn't his wife.
Please don't misunderstand me, what happened was abhorrent and those bastards should be tried, imprisoned and then deported to their country of origin.
However, whilst we have existing laws to cover such events and actions then I can't condone actions (albeit understandable) that fall outside the law. The police should be legally empowered to take action that is necessary, and appropriate, to incapacitate such villainous thugs .......they should not, for example, be allowed to, say, kneel on a miscreant's neck