Postal, in over 20 years at FedEx, I don't recall ever being asked for a boarding pass. Not saying you shouldn't save them for awhile, just in case, but they want the receipt. Think once I submitted a boarding pass because I couldn't find the receipt, and was told they needed the receipt.

If you want to explain the two separate charges, just put a note about it when you submit your expense report, in the comments section.