Stupidity: A prisoner, Jack Williams, rats out Hogan and his team to the Germans, so they fake his death and smuggle him back to London for court-martial. What a stupid thing to do. They should just shoot him and be done with it. First, what if he escaped from captivity on the way through occupied Europe? Second, he has done nothing wrong. Being a grass isn't a crime. Third, Hogan and his men are the war criminals - they often engage in combat activities out of uniform. Williams is going to be acquitted.
Siege Protocol: Part 1 - S3-E11
Stupidity: The team is going on a CQB raid to free some hostages; so close quarters battle, room clearing, a very high chance of getting shot since the enemy can hide anywhere. They are not wearing plate carriers and their armor. This is the very mission that military doctrine emphasizes armor. It's not a long range patrol through mountains where weight matters. However on a previous mission to locate a downed pilot in open terrain they were wearing plate carriers. (00:27:12 - 00:28:00)
Stupidity: With about 5 minutes left, the Black Sheep fly towards a Japanese carrier. They are flying Japanese planes. The Japanese spotter speaks in Japanese. The translation on the screen says "There ours" instead of "They're ours."
There is Nothing Like a Nurse - S3-E10
Stupidity: Hawkeye and Trapper park a jeep over a foxhole to trap Maj. Burns in it. While it is certainly possible to trap somebody in a hole with, say, a sports car, an off-road vehicle like a jeep is particularly unsuited for the task - the chassis has so much ground clearance, even a quite fat man could squeeze out past it. You can even see the gap when the camera cuts to Major Burns screaming "Let me out!" (00:18:10)
Episode #1.7 - S1-E7
Stupidity: When Eugene approaches Tsuda after Tsuda is shot by Ae-sin, Tsuda attempts to shoot him, but after pulling the trigger, he realises there are no bullets in the gun. Seconds later, a group of soldiers run up to him, and he attempts to shoot them, but he can't because the gun is still not loaded. Something he should have known since he only just attempted to shoot Eugene and failed because of it. (00:50:00 - 00:50:30)
Suggested correction: Not true. The crime he committed was treason, a capital offence under both civil and military law at the time. Being a partisan is not an offence under the Geneva Convention, as these were mainly captured flyers, led by a small team of specialists. To execute a prisoner, as you suggest Hogan's men should do, is murder, also a capital offence at the time.
stiiggy
Nobody from Stalag 13 accompanies Williams back to London - so where is the evidence of his "crime"? Hogan and his men often take part in combat activities both out of uniform and even wearing German uniforms, which is itself a one way ticket to a firing squad.