My girlfriend used to work with a guy that was at ups for a while. He said his boss would be the one to push all the packages off the top roller to clear up any jams. He said the same thing about always having to hurry at any cost and they still wanted you to take care of it all with to few guys to get it done.
My favorite one is the youtube video from a homes security cam that shows the ups guy stop at the road(about 40ft from the door), jump out of the truck, and huck the package at the house! LMAO!!!