Is submitter's name on behalf of another user permanently stored?

I looked in PS_EX_SHEET_HDR and found that the field, OPRID_LAST_UPDT, is where the submitter's name is temporarily stored. The submitter's name is not the same as the actual employee where the expense report is created on behalf of the employee.

When the approver approves the expense report, the approver's name then gets updated in the OPRID_LAST_UPDT field, thereby overwriting, the submitter's name.

Therefore there is no way to determine who actually submitted the expense report. Was it the actual employee or someone else who created the expense report on behalf the employee?

The problem at my company is that internal audit wants evidence that the actual employee sees the expense report before it is submitted. If the employee submits the expense report,  OPRID_LAST_UPDT will evntually get overwritten by the approver. Therefore all evidence is lost that the actual employee submitted the expense report.