Has anybody else seen damaged insulation on wire from set screw connectors? If those set screws are tightened too much there is a definite point for damaging insulation to the point of having an unwanted ground.
I have never seen that and don't think that it is even possible to cause damage to the conductors in the conduit unless you replace the supplied screw with a longer one. Yes, the screw does put a "dimple" in the conduit when fully tightened, but that will not cause conductor damage.
Don
