(B) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires shall be securely
fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires shall
be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets. Listed clips
identified for use with the type of ceiling framing member(s) and luminaire(s) shall also be permitted.
The MRC does not address support of lay-in fixtures.
My understanding is normally an additional support of the fixture to the structural ceiling in addition to the framing members is not needed unless it it specified by the design professional. I guess the inspector is going to apply his definition on the word "securely" with respects fastening the ceiling members together and "securely" fastening the framing members of the suspended ceiling to the structural ceiling.