Fun story.
And I would add that, even on the remote times/chance that someone could actually "take everything", there's a few things we have to remember :
1) This is, after all, their property. Thus technically, items belong to them.
2) Even if someone ever truly kept 100%, I would still enjoy it for hunt-sake anyhow. Heck, you can get pix of any notable finds. And thus still have boasting rights among your buddies.
What's wrong with that ? Did any of us get into md'ing to make a living with ?
3) There were actually a few times where I had to "turn over everything I find" (and was truly followed through with) : Those were a few times where I had permission, via my museum docent contacts, to hunt sensitive off-limits historic monument type places. Or when assisting an archie during their digs, etc... But, heck, that's to be expected. Eh ?