FCC §15.219(b) limits the total length of the antenna, feedline and ground lead to 3 meters.
A review of Part 15 AM NOUOs issued from FCC field inspections shows that if an installation does not meet §15.219(b), then they revert to §15.209 to judge its compliance.
If that inspected system is producing a field intensity at 30 meters greater than permitted by §15.209, THAT becomes the basis for an NOUO, rather than non-compliance with any part(s) of §15.219.
So ultimately, those NOUOs are based on excessive field strength.
Whether or not it was intended by the FCC, it is very easy to exceed the field strength at 30 meters permitted by §15.209 when using a 3-meter, base-loaded, Z-matched antenna system driven by many/most commercial Part 15 AM transmitters.
Part 15 AM users generally have been left to sort this out for themselves.