Deliberate mistake: Rampart's ER is located in the south lower wing of the hospital complex and it is only a two-storey building (with a basement), but the elevator, which is located past the nurses' station at the wing's far south end, has two floor indicator panels listing eight floors - one panel over the elevator doors and another we see every time the elevator doors open, which is not possible.
Deliberate mistake: These errors I assume were caused by the show running 3 times longer than the real war. Col. Potter arrived at MASH in September 1952 a year before the war ended, then a few months passed by Margaret got engaged for 8 months, then Frank Burns left and Charles took his place. In this time the war would have ended. In the final episode Margaret mentions Charles has been there for 2 years. Which means he would have arrived in 1951 a year before Trapper and Henry left and Col. Potter arrived. It's a lot to take in.
Deliberate mistake: After Elizabeth goes upstairs with the pillowcases for Cindy, in the following shots there are a few long shots of Colonel Brunson's car on the road, and a couple of those shots are flipped - noticeable due to identical trees shown the opposite way. (00:03:55)