Give an example. What is this "X" you are talking about?
Typical scenario: home inspector says #12 on a 30amp breaker for an AC unit is a defect. My question to them is "why do you think so?"
HIs often write up missing grounds on ungrounded branch circuits. The grounds are missing. If they have three pronged receptacles the only legal way they can exist is for the circuit to be GFCI protected and marked with the "no equipment ground" sticker.
They do, but Ive seen them miss other dangers like MWBC on the same phase, bare EGCs in conduit going to under ground pools, missing main bonding jumpers, ect.
All these could be called a bigger danger then a missing EGC. BTW, something I tell all HIs: never assume a 3 prong tester will tell you an outlet is properly grounded. First check to see if 3 wire NM is leaving the panel (or the separately run ground makes it back to the panel) . A boot leg ground or a ground going to a random ground rod can light a tester on what would otherwise be a dangerous code violation.
If they write that a junction box is loose do they need a code to back it up?
No, because this is indeed a code violation when its being written up.
I see lots of inspection reports where they suggest that GFCI protection be added to kitchens, bathrooms, garage, and exterior receptacles. The code doesn't require this for an existing installation but still a pretty good idea.
In this case if they use the term "recommended" then yes, they are contributing to safety.