"Hap" was an ass.

First of all, what kind of a name is "Hap"? There is nobody in the world called "Hap".
Secondly, he was single-greedy-handedly willing to destroy Dormer's career and thus life (as he keeps on about all 30 years of it), and more importantly, valued his own self-interest above the safety of the streets, which would probably be roaming with freshly-released criminals. OK, so Dormer shouldn't have planted evidence, the cheeky sod, but he did it for good reason. It seems to me that he was more noble, up until he became a murderer, of course.
What am I trying to say? I think it was sad the way "Hap" died, and he didn't deserve to die, but I didn't like him, either.
What's the point of being a detective/policeperson if you're going to value a pay rise (or was it a promotion? I forget the deets) over the imprisonment of criminals? And not just any criminals, but probably the worst of them: rapists, child molesters, murderers. His excuse was that he had "family" but it was just his own he was thinking of. I am assuming Dormer did not.