Character mistake: In the opening scene, Hawkeye and Trapper are operating on a two-star general. But neither one of them or the nurse is wearing their masks. They are under their chins.
Character mistake: As Hawkeye goes to help Maj. Burns right at the end of the episode, he touches the patient with his bloody, contaminated gloves he used to work on the last patient. Such a blatant error would be anathema to any surgeon from the civilized world of the 20th century, let alone one of Hawkeye's caliber.
Character mistake: When Henry is describing the fishing reel he bought for his girlfriend, he said, "with jeweled escarpment" actually it is a 'jeweled esCAPEment" not esCARPment. An escarpment is a long slope off a plateau. An escapement is a latch/release mechanism that you would find on a device like a fishing reel.
Character mistake: Hawkeye and Trapper make Tuttle an alumnus of "Berlin Polytechnic" and translate that (wrongly) as "Berlinishes Polytechnikum". Berlin's polytechnic university was named "Technische Hochschule Berlin" at the relevant time - and at no time offered a medical curriculum. To study medicine in Berlin, Tuttle would have to attend "Freie Universität Berlin" instead.
Suggested correction: And how are Hawkeye and Trapper suppose to know that? They are after all, making all this up. It is never meant to be factual.
It is intended to fool Margret and Frank, so it has to be assumed that they meant to pull it off. Hawkeye says "It can't be any place they'll check", which is why they select a German university in the first place. That shows it is indeed meant to be if not watertight, then at least convincing. To use an university you don't know the proper name of doesn't make sense under these circumstances.