smoke detector placement

smoke detector placement requirements seem to be one of the things that
varys the most between localities, but that's usually in regard to
hallways and bedrooms as far as i've seen. my question is this:
short version: do localities base their building codes on the nec or
the nfac??
long version: i was finishing a rough-in today on a house and had just
finished wiring up the smoke detectors. there was a 25' long hallway
that i placed 2 smoke detectors in on the ceiling about 5' from each
end of the hall, and 6" off the wall. shortly after our lead
electrician comes behind me and rips the boxes off the ceiling and
yelling saying "according to code smoke detectors have to be at least
12in off the wall." i told him he was full of it because the national
fire alarm code clearly states that ceiling mounted smoke detectors
must be no closer than 4in off the wall so my location was just fine.
at that point he claimed that he had failed inspections before for
mounting them less than 12in. he also yelled at me for the one that i
placed in the living room. according to the nfac wall mounted smoke
detectors must be within 12in of the ceiling but no closer than 4in. he
told me that i put it "unnecessarily high" and asked me why i didn't
mount it much lower (it was about an 18ft ceiling). he also yelled
saying that "we don't follow the nfac because we're not installing a
fair alarm system, just smoke detectors. we follow the nec." now i may
have missed a section of the nec, but the only section i can find that
pertains to smoke detectors is article 760. and in article 760 fpn no.
1 clearly says that the nec only covers the wiring and refers to the
nfac for everything else regarding them. i assume that its referring to
11.8.3 - smoke detectors and smoke alarms in the nfac.
i'm just really sick of getting chewed out for doing things that im
almost positive are correct. am i wrong here?? if anyone can give me a
definite answer i would greatly appreciate it. thanks in advance!