Collection attempt pallet with van instead of lorry

Why would a FedEx delivery driver be sent to collect a palleised package with a van? Why did he not know to package was on a pallet? Wouldn't that have been a different type of shipping when it was arranged? Isn't weight, size and wether it's on a pallet or not taken into account when sending a delivery driver over for collection?

This is not to complain, not my problem, just curious what could have gone wrong in this scenario.