No, I'm not. The FAA isn't going to enforce a local ordinance without an FDC NOTAM saying the same thing, and no other sort of NOTAM is regulatory from an FAA perspective. Anything else is merely advisory in nature, and there must be some underlying FAR on which to base an enforcement action (e.g., Runway NOTAM for runway closure due to personnel and equipment working, pilot lands on runway, pilot is done for 91.119 and 91.13, not for violating the NOTAM itself). The FAA would have a difficult (probably impossible) time showing that safety was compromised in a way that violated any FAR just because a pilot back-taxied on a runway -- in fact, 91.113(g) specifically exempts the case of a pilot attempting to clear the runway in order to make way for the next aircraft from the general rule that the landing aircraft owns the runway. If back-taxiing is the most expeditious means to clear, that is compliant with the FAR's.