Undo Warehouse Receipt/Putaway

We were supposed to receive 30 items, but actually received 25. However, the warehouse received all 30, posted the Receipt and then did a Putaway to take goods out of RECEIVING bin and put them into our Bulk Store Bins. When I try to do the UNDO RECEIPT, i get an error saying there is insuffiecient content in Bin. would this be because it is looking for stock in the original RECEIVING Bin. what would happen if I transfered the 5 cases back to RECEIVING - would it UNDO RECEIPT then