Just watched the scene with them running through the maze again with closed captioning turned on. There’s a place where Gareth yells “Get them off B!” There are about 3 doors labeled “A”, so there must be an “A” path, which is the trap that ends at the boxcar, and a “B” path.
Also, there’s a place where you see a couple of containers and you hear some people yelling ‘Help!” and “Let us out!”, and Daryl says “What the hell?!”