On the other hand,
a) He's in his 30's and should know better.
b) He has no rapport with OP and knows basically nothing about her.
c) This is a pattern of behavior that women in the industry have to deal with all the time, not just an isolated incident. (See the comments in the thread.)
When I look at issues like this as a guy, I have to remind myself that "feeling sorry for the perpetrator" is in fact one of the many anti-patterns that leads to this kind of hostile environment in the first place. So I cannot judge the victim for whatever decision she makes.
Were I in her shoes, I would probably send the guy a harshly-worded e-mail instead of escalating to HR. I don't like the idea of someone losing their job over a really dumb decision they made in the heat of the moment. But I am not a woman and I haven't had to go through life getting worn down by dozens of incidents like this one, so my perspective here is kind of meaningless.
It's really nice to give this guy the benefit of the doubt. Maybe the girl was just so perfect he could't help himself and it was a one time thing. I don't know but honestly you really need to consider the converse. What if this isn't a one time thing. What if this is the way he acts whenever he interviews a woman. This absolutely needs to go to the proper persons (eg HR, CEO/CTO since they might not have hr) who can handle the situation.
They address problems for this for the company. HR is there to defend the company, not the employees.
Letting HR know about the incident will likely cause this person to be terminated.
I'm not saying OP should or should not do it, just clarifying the consequences.
Personally, I think what this guy did is
- a bit creepy
- pretty mean since he probably turned her down so he could ask her out
Having said that, what he did is NOT
- sexual harassment (there is no authority relationship at play)
- abuse of power
HR doesn't generally have the ability to decide to fire people. So if this person's bosses, in consultation with HR, think this is worth terminating someone over, that's certainly their right.
I don't want to parse words with you, but this is wildly inappropriate behavior and it certainly should not be ignored. HR is the correct department to make sure it gets addressed.
And, frankly, some companies may believe that "creepy" and "mean" behavior on its own is a serious offense even if, as you assert, no abuse or harassment occurred.
Harassment, no. That's simply not harassment.
Also, nearly this entire post's comments are debate. There are people on both sides. This issue is not black and white, anything but. If you read some other comments, you will see it's not so "overwhelming." A majority, yes. Overwhelming, no.
I'm not saying he should be fired but professionalism is required at workplace and this is an abuse of power.
He knows it's wrong and did it anyways. I don't think I'd consider that a mistake.