Well I wouldn't so far as to argue that, but I should like to make a few additions.

First, I think Vimes is talking about guilt in general, not necessarily of being guilty of a crime, per se.

Secondly, I think Carrot is canonically the only actually law abiding citizen, yeah, but... that would still leave at least Vetinari, who makes the rules, no?

I wanted a quote from Vetinari here but there's too many so here's a couple. First, description, not a quote.

"He didn't administer a reign of terror, just the occasional light shower."

And

You see, the only thing the good people are good at is overthrowing the bad people. And you're good at that, I'll grant you. But the trouble is it's the only thing you're good at. One day it's the ringing of the bells and the casting down of the evil tyrant, and the next it's everyone sitting around complaining that ever since the tyrant was overthrown no one's been taking out the trash. Because the bad people know how to plan. It's part of the specification, you might say. Every evil tyrant has a plan to rule the world. The good people don't seem to have the knack.

One more for the road

If per capita was a problem, decapita could be arranged