It’s not shifted, its shared by way of a lawful order. The Master and owner will be held accountable for violating the COTP order but crew could be held accountable for not following lawful orders and in doing so creating a hazardous condition.
If they were secure dockside (read as no hazardous condition would be caused by the absence) I agree with you. No employment agreement regarding work schedules and no shipping articles your good to go.