Resolution:
The work item is purged from the WIS cache, so therefore there is no account of it after the deadline - withdraw, even if data has to be kept
(foreground) or released (background).

The deadline is the most important factor in all this and the user has been too slow to keep or release data.

Therefore, if you want a user to act on a workitem but you know there is a deadline associated with that step, always allocate an acceptable amount of time for a user to enter data and release it if required.