Having sat in court for two days wile i mate of mine was in the dock for breaching rule 5 wile teaching EFATO the whole CAA case was based on his "reported" proximity to persons and houses.
He was undoubtedly nearer than 500ft to a fence but the CAA took the view that it was the houses and people that matterd.
As it happend the case was dismissed but im sure that if a fence was within the bounds of rule 5 then the NIMBYS who (in my opinion) fabricated the evidence for this case would be crying fowl by now.