The troupe of actors is heading north, as they tell Nicholas at the campfire, but when they come to a collapsed bridge shortly afterwards and debate whether to go west or east along the river, they point to their right as being west, which is the wrong way round.
Writing with the left hand was considered a sin in the Middle Ages, and would never have been taught to a monk. But Simon Damian has learned of his own accord to do it when nobody is looking.
Brother Simon Damien is shown holding a pen in his left hand, but the position of the quill in the scenes where it is writing indicate a right-handed grip.