When Potter and Charles are playing gin rummy in the tent, Charles proclaims 54 points. He then reaches for a notepad, but in the next scene, he's already writing on it. The notepad then disappears and reappears on the table between shots.
Throughout the episode, Loretta Swit's fingernails appear to be almost an inch long. No nurse, especially a head nurse, would have fingernails that long.
When Winchester plays the Caruso record and Colonel Potter takes it off the turntable, the person who throws it is not Potter but a stand-in who's much taller than the colonel.
When Potter comes down with the mumps, a replacement surgeon is requested to fill in for him because a lot of wounded are expected. But when Winchester also gets sick, a second replacement is not sent for.