Because the Post Office isn't filled with observant dedicated professionals? Which you would have agreed to until your conspiracy theory.
A crazed moron living in a van that can't build a functional device also can't calculate postage? Shocking.
No package gets into the mail stream without being checked out. You cannot put a package in the mail, you have to go to a window. If you put it in the mail, it gets separated and examined. All mail is photographed and given a bar code.
Whatever happened, these packages were not mailed.