Visible crew/equipment: After Colonel Potter gets off the phone, he tells Klinger about Torgy Porgy and how after four years of medical school Torgy washed out, and just as Potter and Klinger stand up lighting equipment can be seen at the top right side of the screen.
Visible crew/equipment: While Major Burnham watches everyone at work in the OR, just as Charles says, "If you'd care to step over here, Major," the boom mic dips into view at the top left side of the screen.
Visible crew/equipment: In the scene following BJ's shower, when Hawkeye and BJ enter their tent, you can see the tip of the boom mic drop for a couple seconds.
Answer: Even an Army field hospital would have SOME weapons for self-defense if the enemy attacked. What's meant is that it's not a combat outfit, and therefore wouldn't have enough weapons to actually attack anyone. (It's also mentioned a few times that the Officer of the Watch is supposed to carry a pistol at all times, but Hawkeye refuses to do it when he's in charge and Colonels Blake and Potter don't enforce the rule).
Captain Defenestrator