If you use an RF scanner and you know the approximate time and date the order was picked, you can use the Task history report, which you can view by following the steps below:
Go to the Stock Maintenance tab at the top of Delta
Select Reports
Open Reports
Open RDT Reports
Select Task History Detail report
Press Run
Enter the Site
Then a Start Time and Date
Then an End Time and Date
This will show you all tasks performed within that time.