Considering how quick he was to admit to blackmailing her, he must either have been a total moron trying this for the first time. Which all things in this matter seem to indicate against, indeed.
Or he had done this so often, he felt he knew how the rest of the conversation was going, and he just decided to get to the point before wasting any more time. Accepting to have this on his record forever more does suggest he feared other stuff would come out in court.
One can but hope that, wherever he moves in the future, it'll be a place where, for the rest of his life, he'll have to personally inform every single one of his neighbors of what he did. And that, with that stain on his record, the only sort of job he'll be able to get will force him to live in the kind of neighborhood where people are disinclined to like police officers to begin with, and will have particular appreciation of a dirtbag cop abusing his office as he did. Make his whole life real damn unpleasant.
"Okay, so you're reporting an assault, you got beat up by your neighbor, let me just... hang on... oh, you used to be one of us? Well, brother, we'll sure... hang on... you fucking did WHAT? Dirtbags like you is why we have to wear body cams and attend all those fucking seminar! You know what, fuck you. Your neighbor was evidently acting in self-defense. Fuck off, or I'll arrest you, and I'll let anyone in the tank know that you used to be a dirty cop!"
If there were absolutely anything to be afraid of, don't you think I would have worn pants?
I said I have a big stick.