Scotty, no mention of tail gunner, merely gunner.
punishments have been administered to those of military beginnings for referring to an aircraft as a plane
Must be a RAAF thing. One of the military services in which I served referred to them as planes all the time. That ranged from single engine put puts, to fire exhausting heavy metal. Even had people whose title was "Plane Captain" and it wasn't the guy who sat in the front seat. They marched to a different beat obviously, very little is ever cast in stone.