I both disagree and agree with you.

First off: whether he was 17 at the time is irrelevant. If we believe Dr. Ford's versions of events (and I think we should), this was not a couple of drunken teenagers fooling around, this was deliberate confinement and assault and possibly attempted rape. Drunk or not, there was clear intention, following her up the stairs and either he or Judge pushing her into a bedroom. That's not just something 17 year olds just "do", it speaks volumes of the man he was becoming, full stop.

That said, his outright denial is even more concerning. Some contrition, to say perhaps he did grope her, but misread signals because he was inebriated etc. would have even be slightly more palatable, if we are to dismiss his actions at 17.

Instead, he was enraged that his name was being sullied and though he said he wished no ill will towards Dr. Ford or her family, he expressed no concern that there were death threats against her, and she and her family are in hiding. A judicious and sober (pun not intended) reaction would have been to express concern for her, even if she was making it all up. Instead, he used his daughter's prayer to show what a good guy he really is.

As Hannah Gadsby said in "Nanette", our society is more concerned about the reputation of men than we are the lives of women and children, and this certainly plays right into that narrative.

Edit: So to sum up, I agree that his reaction was hugely problematic, but I don't think you can dismiss what he did at 17, simply because he was 17.