Bob, no one is perfect, not you, not me, not the CMP and not Mr. Holt. We all make mistakes and in this case "they" are all wrong.
You are 100% correct about all of us making mistakes.
However in this case it is you that is mistaken, you are in great company but you are still with out the slightest bit of doubt in my mind mistaken.
Unfastened conduit in open trusses is most certainly subject to movement beyond what the couplings would safely withstand, from accidental contact, hanging loads, deliberate contact and possibly even seismic movement. Heck, in a long run even the forces of pulling in the conductors could cause couplings to separate if the conduit is not securely fastened.
And in the ROP the the CMP is looking for real evidence that is an actual problem not just a perceived one.
Lets go back to a 2x4 stud wall I run 1/2" EMT 50' horizontally through however many studs. In this case the holes are 1.25". Am I required to securely fasten the EMT every 10'? (Assume that it is securely fastened at the termination points)
Yes or No?
Simply lay one in the truss webs and secure the other at no more than 10' intervals as required by Code.
Pick any size and numbers of conductors to equal 75% fill.
Pull those conductors into each run and see what happens.
At the absolute minimum, I promise that the unsecured run will be moving around and making the pull harder, IF none of the couplings don't pull apart.
Of course it would move, you did not secure it within 3' of each termination.
But you also assume that just becuse it can move means it violates the code. That is a falsehood.
The 10' rule is there for a reason people. :grin:
There is no 10' rule for EMT horizontally run through framing member not matter how much that bothers you.