Revealing mistake: When Jim is riding the bicycle through the empty hospital, the "Frigidaires" begin falling through the roof. One bursts open, dropping its contents onto the floor. Something from inside must have landed on the camera because you can see it jerk suddenly.
Revealing mistake: At the party, Jamie finds the crashed plane. His glider falls behind a small hill and he gets out of the plane to see where the glider is. When he jumps off the wing, the camera is panning to the side, revealing somebody on the left side walking on the hill, right under the tail of the plane. Jamie should see this person but still reacts shocked to see people are behind the hill. (00:17:00)
Chosen answer: The first time, Jim says "Nanika no machigai desu. Bokutachi wa minna tomodachi desu yone. Senso no sei desu." This roughly translates to "There has been some sort of mistake. We are all friends aren't we? It is the war's fault." The second time, Jim only says "Nanika no machigai desu. Bokutachi wa minna..." and then gets pushed aside. "There has been a mistake, we are all...". I hope that helps.