Continuity mistake: While Colonel Potter is painting the portrait of Charles, the portable military field desks behind Potter are all open - note the front doors are flipped down, but in the closeup of Charles holding the painting of himself the doors are folded up. And the books, etc. atop the field desks change as well.
Continuity mistake: While Charles is reading the letter about his nephew being discharged because of fainting spells, Klinger feigns a fainting spell falling forward onto Hawkeye's cot, and his body lies lopsided with his leg hanging off, but when it cuts to the next shot Klinger's perfectly positioned on the cot. Also, note the mail Klinger tossed earlier onto Hawkeye's cot, near his pillow, is now neatly tucked under the blanket towards the foot of the cot.
Continuity mistake: While Charles, BJ, and Hawkeye are in the Officers' Club, when Margaret storms in and starts yelling at Charles about the visiting pervert Colonel, Charles facepalms himself with his right hand, but next shot his left hand is up, and it continues to switch.
Visible crew/equipment: While BJ, Hawkeye, and Charles are in the Swamp, when BJ starts reading the letter from the child who thinks the army is like camping out Charles takes that letter away from BJ, and just as Charles is about to sit back down the edge of the Swamp set can be seen at the top right corner of the screen.
Visible crew/equipment: When Sidney arrives and speaks with Klinger in the office the door remains open for the next few shots, and while Klinger first talks to the doctor and then to the driver, we can see the top of the crooked "sky" backdrop behind the tent in the compound.
Continuity mistake: When Colonel Potter, BJ, Hawkeye, and Charles are in the changing room, Charles wants to be alone so he takes his tan jacket off the first nail on the right and leaves, but in BJ and Hawkeye's closeups the tan jacket is still hanging on that first nail, then it vanishes again.
Continuity mistake: When BJ, Charles, and Hawkeye are in the Swamp getting drunk they toast to "war, the fountain of loveliness," and Charles attaches the surgical clamp to BJ's hand and it dangles with the end facing out in the closeup, but the clamp faces the opposite way in the wideshot, then it's changed again.
Visible crew/equipment: While Colonel Potter, Margaret, and Father Mulcahy are in the mess tent, we see that BJ and Hawkeye arrive back at camp in the jeep, and when they walk into the mess tent the curved chalk foot marks can be seen on the floor under the table, between Potter and Mulcahy.
Visible crew/equipment: When the guy from I Corps Supply lifts the flap at the back of the truck with all the boxes, just as Colonel Potter says, "Sergeant, how many of these parcels are checking into this post," the shadow of the boom mic can be seen at the top, right corner of the screen.
Visible crew/equipment: In the overhead exterior shot of the compound, when Colonel Potter calls everyone's attention to the situation regarding "crackerjack corpsman" Sergeant Hutchinson, as the shot pans out we can see the boom and the boom mic at the top left corner of the screen. Then when Margaret calls on Hutchinson to come forward, the boom mic is moving around at the top of the screen, and it's still there when Klinger rides out on Sophie.