If you sign for the jet or are coded as an IP/EP you are responsible per 11-401 and I think you can log it. The tricky part is when you give an eval to a guy who signs for the plane and you just hop on. That is a bit grey. Since no airline can prove who signed for, I say call it PIC, just know that the airline answer is "did you sign for the plane?"

If there is no multipler for mil guys at a particular place(NJA has one but doesn't advertise it) I would suggest adding .2 per sortie to compensate for taxi time.

Bottom line, you will have to be able to explain it at an interview. I took the painful step of getting a new Jepp professional logbook when I got out and redid all 8 years of flying with taxi time added in, if asked, I would say that the time is logged IAW the FARS, when the acft is under motion. If an airline doesn't want that, they will specify on their website usually, just like PIC, Delta or United specifies PIC on their website.