Someone puts a knife to your cheek. Hesitant threat response makes you freeze. Will you fight back or let them take their advantage b4 they take off?

I took the knife away from someone holding it against the throat of a woman I know. The fellow and his ex wife were not on the best of terms so he pulled a knife. I pulled it away and about 6 guys jumped the guy with the knife and held him until the police arrived 20 minutes later.