In the latest episode, a Nights Watch member just leaves his assignment/task/mission before completing his assigned objective with no excusing reason.
As he is going back I don't think it counts as desertion, but is there any punishment for this under normal circumstances at least in the show or book?
Sam leaves the Citadel without permission or affirmation from the maesters thus violating his mission of becoming a maester for the Nights Watch. He also steals a few books. For the purpose of this question we will ignore what he may have been doing with Gilly