Did you see him take the contents?
Was it not a box that was damaged and the contents were already missing, spilled, broken and the guy threw the empty box to get it out of the way?
I have alot of questions about this one. To say that he is an "accessory after the fact" is a bit strong and overblown. The author of the thread infact never said he SAW THE PERSON STEAL ANYTHING. Just said he saw him throw an empty box.
Honestly, it's possible it was NOT stealing and just one of those situations where the unloader SHOULD throw the empty box outside the trailer and let someone else deal with it.
If I was the author, I would not say anything given he/she did not physically and 100% see the person open the box and pocket the contents. If you did see them stealing, period, no questions asked, then report it.