You'd be surprised: this isn't like in America. Public perception and reputation mean a lot when it comes to police force promotions over here.It's England, I doubt it will even occur to her that she can fight back against the pig.
One wiff of any type of scandal? Yeah, you're bad PR unless you've got serious "old boy club" backers, so you're gonna be a street bobby until you die, retire, or quit.
If she complains, this guy is basically fucked: hell, he may be fucked already with it being news on the internet. If his identity is revealed? Yeah, RIP career.
Edit: and I totally misread your post. I thought you wrote "I doubt it will even matter"/along those lines.
In my defence, I'm a bit hammered at the moment on vodka. energy drinks, and brandy. My bad.
Yeah, she needs to write a complaint or make a stink of this. This guy needs to be kicked in the nuts.
A mistake is fine normally and learning from a fuckup like this would be good normally, but if he gets promoted and carries this attitude upwards? It'll cause ripple effects on anyone below him. Nip this cunt in the bud now.