I figure that this 23 year old cop with only 2 years on the job, was trying to impress 21 year old Shannon McDonald with some of the comments he was making. He should have been formally counseled for his behavior, if it was proven that he actually said what the journalist claims he said. But calling the criminals in the district "f-ing animals" is not a reason to dismiss someone.
Look what happened to Mark Fuhrman and that was in 1995. It is much worse now.
You're exactly right as to how this should have been handled.
"Praise in public, counsel in private..."
The story here is about a breakdown in management and supervision. This is why 23 y.o. cops have superiors: To serve, counsel, and sometimes protect the newbies from themselves.
We've all been there.