[Andy A.]

The short answer is that, no, this is not ok. However the mounting screws for the PDB should not be a source of a frame fault. I'm honestly not sure how they could be.

The far more likely candidate is the Crio; the chassis of this does need to be electrically isolated from the frame. Another possible fault is the camera which, apparently for some models, is also a frequent culprit.

Check the C-Rio again, carefully.