On a side note, I worked at Fedex Ground 4-5 years ago where I loaded the 53 ft trailers. The packages come in too fast for the guys to handle so a lot gets dropped into the bottom and stepped on or crushed by other boxes. I don't remember anything ever being thrown, the supervisor at this particular location watched every move to make sure things didn't happen to packages. He was a good guy. If things get damaged there really isn't anyone to blame from what I saw
I took a tour of UPS as seasonal job 5 years back and would say I didn't see anything being damaged. The whole operation looked extremely smooth at said terminal.