Order Fulfillment and Pricing

My users were doing some research on invoices and found an invoice in history that has a zero price.  When they reviewed the order in the sales ledger, they found that the order had a price until it went through the batch order fulfillment (R4277701).  The order had 65 lines on it and all 65 lines had a zero price after it went through fulfillment.

I've looked through R4277701 and don't see any logic that would reprice an order.  There are business functions that it calls which I didn't review.

I'm looking for thoughts on what would cause the price to be removed from an order as it goes through order fulfillment.  We do not have any customizations to the process.  We are on version 9.1.