How in the hell do you lose a backpack with $3300 in it? Why the hell did the kid have $3300 in a backpack? I'd have it in my pocket and be OCD feeling it every few minutes. I OCD feel my wallet all day long.
Homeless guy might have been justified returning it missing $1000 and leave a note explaining it was a ******* tax for losing it.
I take it you've never made a very large purchase and brought cash for the negotiations. Even chain stores will come down on the price of a big ticket item if you have cash in hand and talk to the right person.