It's taken me a while to flick through (i.e. not thoroughly watch) the Coy and Vance episodes, but I have to agree with the others. The nearest thing I found was when Coy throws Vance some groceries near the start of 'Witness: Jesse Duke', and Jesse's in hospital when that happens.
As a reminder, here's a screengrab of the scene from the opening titles.
I spotted another small blooper when I was skipping through 'Mrs. Daisy Hogg' the other day. When Rosco's patrol car has its first impact, it loses its front end (fenders, hood, grille etc.), but the shot of the occupants immediately afterwards shows the fender still in place.