Wow, it didn't even occur to me to report it. But you are right, I should have.
I absolutely don't blame you for not reporting it (that's a pretty goddamned nasty thing to do to a friend after all) but I don't envy you your contemplative time alone, considering the high likelihood of this officer having made a number of new victims since you heard the sheriff's anecdote.
That said, I imagine it's a similar situation for the cops. Nobody wants to be the arsehole who rats out their workmates
Officer cams that can only be lawfully disabled during a shift for restroom breaks (for example) would go a long way to helping clean this situation up, but only if the footage is well outside the Police's control. I'm fed up to the back teeth with the foxes running the henhouse when it comes to police conduct.