Resolution:
Description: Entries in TRIGGERED_ACTIONS table can interfere with IcAuditManage event
deletion.  

Note if they can wait along time have them set IC_TIMEOUT to a large value, say 3600 seconds
which is one hour.

Determine if this is the problem by issuing one of the following SQL queries:
SELECT COUNT(*) FROM TRIGGERED_ACTIONS;
SELECT EVENT_ID, COUNT(*) FROM TRIGGERED_ACTIONS
GROUP BY EVENT_ID
ORDER BY EVENT_ID;
SELECT TRY_COUNT, COUNT(*) FROM TRIGGERED_ACTIONS
GROUP BY TRY_COUNT
ORDER BY TRY_COUNT;

If the counts are in the tens of thousands there may be a problem.

Give them code only with the understanding that they should never do
any direct manipulation of the ICDB database tables unless they are
directed to do so by Customer Support.

If this is the problem, you can delete old entries with the following SQL:
DELETE FROM TRIGGERED_ACTIONS
WHERE TRY_COUNT > 3; /* fill in a number of your choice */
and try IcAuditManage again.
As a last resort, it is OK to delete directly from EVENTS using SQL.
DELETE FROM EVENTS
WHERE EVENT_TIME <= `FILL-IN-THE-DESIRED-TIME-HERE';
The only issue here is that if an event gets deleted that is referenced by
TRIGGERED_ACTIONS, then the next time the server retries that particular action it will log a database error and not retry again.