Claim not referred to Expense audit when claimant is on the Expense Audit List

Summary:

Claimant was placed on audit list for high number of expense claims in a month.

The first two claims were sent to audit for review. The 3rd claim was not sent. Claims following this were sent until the end date of the audit period.

Looking at the audit list history for the claimant, the claimant was place on and off the audit list, by the system, 3 times on the date that the claim failed to go to audit.

I have checked the claim to confirm that the claimant did not withdraw and resubmit the claim.

Please can you advise the possible reasons for