Theory:Doctor Who television discontinuity and plot holes/Flatline


 * After the train get flattened, Clara finds the Tardis in siege mode, and the run. Next thing we know they are in an office. Then, Rigsy has the time to draw the fake door, then they find there way back to the tunnel. This whole time the 2D beings are no where to be seen, but at every other point in the chase they were always seconds, or at most, a minute or two behind.
 * They were hiding from the beings. We don't know how long all of that took, but it didn't have to be more than a few minutes total.