I believe the last 2 points because I don't believe that credible military personnel with long and distinguished careers, would tarnish their reputations terribly for no apparent gain, especially near the end of their lives.
Check out Philip J Corso or Robert Salas, but there are , many, many others who have blown the whistle including Walter Haut the public affairs officer during the Roswell crash (and recovery).
https://en.wikipedia.org/wiki/The_Day_After_Roswell
https://www.disclose.tv/capt-robert-salas-ufos-shut-down-nuc...