On the old processing screens there was a way to mark an order as "error" which would put the order in an error status on the customers side of the system.

The option to mark an order as error should also be available from the new processing screen as well. Marking the order as error would bill the client back for the picking fees since the order could not be shipped after the work had already been done. Also with the ability to add a reason. i.e "This is an international order but there are no sell prices assigned to the items"