Followup to this...
This morning I was working on a spot that had a bunch of 3D qualifiers on it. When I was zoomed into the frame, I saw a single "speck" on the frame, and was trying to figure out if it was a hole in the qualifier, or an actual dead pixel. When I toggled the grade on and off, the "speck" remained. So I added a Dead Pixel Remover ResolveFX to a new node, then noticed the speck disappeared. It wasn't until I zoomed out again that I realized that the "speck" was just an errant "Show Paths" trace.
Another reason why I'm not a huge fan of having "Show Paths" on by default.