Mudkow,
Unfortunately, the person at the airport is wrong.
The following regards submitting military time to the FAA for the purposes of qualifying for FAA ratings. Doc's FAR website has a lot of discussions around this subject, and good references given in the discussions. Use the search mode:
http://www.propilot.com/doc/bbs/
The rule of thumb is that you either have to be the assigned aircraft commander for the flight, or you have to actually be twiddling the sticks. Specifically:
You can log all AC time as PIC.
When not assigned as the AC for a flight, you can still log all FPT as PIC if:
1) You are a rated military aviator (some exceptions when you can log flight school time as PIC, see below).
2) You are AC rated in the aircraft (some exceptions here too, see below).
You cannot log CPT as PIC if you are not the AC on the flight. It doesn't matter if you are rated as an AC or not.
Exceptions:
Flight school time:
1) You can always log solo time as PIC.
2) You can log FPT as PIC before you get your wings, providing you hold an FAA rating for the aircraft category and class, and providing the aircraft does not require a type rating (unless you hold that FAA type rating). So if you had an FAA SEL rating when you were in primary, you could log all your T-34 FPT as PIC.
PIC time if you aren't AC rated:
1) You can always log solo time as PIC.
2) If you are a rated military aviator, and are flying an aircraft that does not require an FAA type rating, and you hold the appropriate FAA category and class rating, you can log FPT as PIC. So if you got your FAA rotary wing ratings sometime after your first helicopter AC check, and then snagged a left seat ride in a UH-1N (small helicopter not requiring a type rating) you could log the FPT as PIC.
Times you can't log FPT as PIC:
1) You aren't AC rated and you don't hold the required FAA category, class, and type rating (as applicable). The CH-46 has a civilian type rating required to act as PIC, so you couldn't log FPT in it as PIC as a non-AC unless you held that FAA rating.