Scott where did you get your figure of double?
I have seen some knowledgeable people state the effect is negligible, certainly not double.
Not busting your chops, I really want to know the truth and am curious to what you have seen.
I do agree it should be bonded, no matter what else the code requires it to be bonded.
I still do not see a terribly dangerous situation.
I was actually coming back here with some code references but you already provided one of them.
Here is another, 250.64(B) tells us that when the GEC needs to be protected from physical damage it "shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor."