I have seen a number of incidents where situations like this came up.
1. Going for my 135 CP ride with a company that flew 210s and 310s. The POI wanted to see my HP/complex endorsements even though I had type ratings. He said it was silly, but required for our operations. For those who think you do not need a HP/complex endorsement to fly 135 I would strongly differ. If the aircraft does not require a type rating, then it would require an endorsement if it meets the requirements of 61.31.
2. I did a contract to train a military pilot for his CFI. Pilot needed the complex endorsement to take his check ride with the FSDO and the FAA inspector did check. In addition, even though this pilot had flown military TW aircraft (yes, the military does have one or two around), he needed a TW endorsement to fly the civilian TW aircraft. Just as there was nothing in the regulations to cover the complex/HP endorsement, there was nothing to cover the TW endorsement.
There are no legal decisions or interpretations on the endorsements required for military pilots. There is only the regulation and legal precedents on log book endorsements in general. In the absence of the former and the presence of the latter I would strongly encourage pilots to get the endorsements unless you want to be the guinea pig. Being the guinea pig before an NTSB judge can be very expensive and detrimental to a career.