... So just maybe it is compliant.
The reality that a given unlicensed operator/operation reportedly has survived an FCC inspection without generating an NOUO may or may not prove functional compliance with Part 15.
There have been posts on various Part 15/Community websites stating that "whip and mast" Part 15 AM systems using long, radiating paths to r-f ground (something buried in the earth) have been inspected and passed by FCC field inspectors.
Yet in other cases they have generated FCC citations.