Re: Security or Marines?
Can you imagine what would it would be like if anyone of superior rank could come along and change a brig guard's orders?
I can, but who says Kirk and Sulu were doing anything of the sort? Kirk come to visit McCoy. If he wasn't supposed to be there, the guards should not have allowed him inside the cell and should instead have asked him to wait until McCoy was moved to the appropriate psychiatric facility.
"He clapped his captain—his friend—on the shoulder. Yes, this man was very much like James Kirk, in all the ways that mattered." --Christopher L. Bennett-- Star Trek: Mere Anarachy, The Darkness Drops Again