Throughout the episode, Loretta Swit's fingernails are over an inch long. No nurse, especially a head nurse, would have fingernails that long.
Hawkeye tries to get a jeep delivered and accidentally gets an M8 pack howitzer instead. The soldier who drops it off easily lifts it. However, moments later Alan Alda and Mike Farrell are obviously pretending to be unable to move it. In reality, the weapon was balanced on its wheels so that a single crewman can lift it by its rear trail to shift its position.
In post-op, when the doctors are asking for volunteers to try the skin cream, the end of the wall in post-op is visible on the left of the screen with a member of the crew visible behind it, wearing a white shirt and dark pants.
When B.J. and Colonel Potter discuss trying the tree bark remedy, they decide to try one patient "as a control". However, controls are patients who get standard medical treatment and their results are compared to other patients who get the experimental treatment, which in this case is the tree bark, to see which one is better. Although laypeople may not understand the difference, medical doctors clearly should know.
Hawkeye wants nothing to do with owning the Howitzer and tries desperately to get rid of it. In fact, when Col. Potter first sees the weapon, he tells Hawkeye that "We're a non combat unit and we're going to stay that way." He also tells him to get rid of it before it starts drawing enemy fire on the camp. Yet, in season 4, the camp comes under enemy fire, and the first thing that Col. Potter suggests to solve the problem is to park a tank in the middle of camp to scare off the enemy. He tells Hawkeye that it's like having a big dog in your yard to scare people away. Hawkeye seems to have no objection to this and in fact calls a colonel that owes him a favor to leave one of his units tanks in the middle of camp.