I also believe the soon-to-be-late redshirt isn't an ensign at all (they have one thin stripe on the cuff), but that rarest of beings, a Starfleet enlisted man. Starfleet seems to be the only organization in the galaxy made up of 99.5% officers.
That could also explain why the greenest of ensigns still get individual quarters aboard a starship the equivalent of a Second Class cabin on a cruise ship.
Heh. That's what my Dad used to say:"They've only got officers in this outfit."
Judging by the way "Ensign Ricky" is holding his weapon, Kirk may become the victim of friendly fire.
"Let's see how you like wearing the red shirt, Captain!"