Rejecting Duplicate Line on a Multi-Line Expense Report

We are testing Duplicate Detection Functionality and have come across an issue when AP audit a multi-line Expense Report containing a duplicate Expense Line (entered on a previous Expense Report). Detection has been set up to warn the user but still allow them to submit the Report. After the Manager has approved it it hit's AP for Approval (always will due to it being a Policy Violation). AP Verify the receipts and mark the duplicate line as a Policy Violation after which the Audit is completed at which point the report is split with a '-1' report being generated. The