They made it because they went off on their own and avoided the prime escape route most of them took. Cedric was the best. He biked his way to the town to get Resistance help. Danny and Willie went the ship route and off the radar. The last person I would have followed was Roger and Mac as there were bullseyes on both of their heads. Ashley Pitt was a hero in sacrificing his life for both of them at the train station. Mac made the mistake he warned the others about. Reactively speaking English. He got Roger and him caught with that gaffe. Henley would have made it out without worrying about a blind man.
The scene is undoubtedly one of the highlights of the film, but it doesn't fit with the real chronology. The real outbreak was in March 1944 and therefore this scene would have to show July 4, 1943. But in the film, not much time passes before the outbreak, certainly not nine months.
You're correct that this happened in 1943. My father was there and wrote about it in a letter to his parents: "Today is 4 July, and early this morning at 8:00 the Americans led by a band playing American marching tunes traipsed through all the barracks, whistling, screaming and shouting like Indians; one Major I noticed was dressed in an Uncle Sam outfit. Shouts when passing our door were: The Indians are coming! The war is over, The British are coming. While on parade, 3 Yanks as a horse waddled onto the square. Great fun, when the “horse” finally tossed the rider off and galloped back."
