No harm has been done, so I probably wouldn't stress about it too much.
I am slightly struggling to picture it. What actually happened? She "tried to hug him" - did she verbally ask for hugs? Or come towards him arms open, and he dodged out of the way/pushed her off? How often?
Likewise the "trying to buy him drinks". Did she buy them but he refused to accept them? Just keep offering to buy them and he kept saying "no"?
My point is, none of us were there, so we don't know exactly how it went. We only have your DH's account and I am not saying he is lying, but it's how he saw it - others may have interpreted it differently.
And of course it isn't the same as a man doing it to a woman. Women just don't pose the same physical threat men do. I am not saying it's great of her to do.... Whatever she did.
My take on this will be an anathema to most on here, I know, but I don't think anyone belongs to anyone else. When she spoke to your husband she was not somehow messing with "your property".
He has free will and agency. If he had decided to cheat on you because a woman hugged him and bought him drinks - what of any worth would she be stealing? A faithless husband who doesn't stick to the rules of your relationship (which is, I assume, meant to be exclusive).
Why would you want to keep that, anyway? Why anybody would want to remain in an exclusive relationship with somebody who only stays loyal if not given the opportunity to cheat, is beyond me.