Behavior of Credit Card Transactions Marked as Personal for Individual Pay

Summary:

Credit card integration with American Express has been implemented for the US with the Individual Pay option. Sometimes employees create expense items manually instead of adding the credit card transaction to the expense report. The guidance has been to mark the credit card transaction as personal so that they are not categorized as outstanding. An employee recently left the company, and his supervisor received a list of Corporate Card Expenses Awaiting Submission. All of the expenses were marked as personal and had corresponding manual expense items created, submitted and paid.

Why were these marked as personal expenses deemed outstanding?