In the O.R. during the shelling, while Hawkeye is singing it appears as if he is sopping up blood with a sponge, when the sponge is show again it is completely clean.
The long fingernails seen on Loretta Swit are too long for regulations.
When BJ is reading the letter from Peg, the fourth side of the tent is missing, evident at the upper left hand corner of the screen.
When Brigadier General Marion Prescott (Dick O'Neill) gets stung by the bee, you can obviously see his neck isn't swelling up when Hawkeye wheels him back in to be check out.
As the general and MPs drive into camp, a spotlight is seen reflected in the windshield of the MP's jeep. Later, a light is also reflected in Radar's glasses as he is trying to catch one of his bees.
When the General's jeep enters the camp it is flying two General's flags on either side of the jeep (designating it is General's jeep). It was on its way from the front where the General was hurt. NO flag officer would be on the front announcing to the enemy that a General was present. That would be like putting on a "Kick Me" (or in this case a "Shoot Me") sign on your own back.