Mike it appears that you have missed the point. I thoroughly understand what you have been saying - and have had a number of such 'pitches' made to myself in the last few years. In fact I turned two down in the past two months. The only one I signed for had specific clauses that anything found is going to the searchers and not to the outfit (which was not Go-go-lucky productions by the way) and it was also specifically not scripted. I would think that you would be wise enough to make sure to insert the necessary clauses in any contract before you put ink to paper as I did.
When and if you get the "right" offer, you won't want to turn it down.
Suppose you were offered all the financing needed,
all expenses covered,
not scripted, no added 'character' type people added to your 'crew' with or without your consent either, AND you were going to get paid on top of everything? You could not think of a treasure you would love to go hunt for, and allow the film crew to capture the adventure on video, while you get paid whether you find anything of value or not?
All that said -
your advice is well founded, to all treasure hunters considering taking the offers of these various TV producing outfits - make sure you know what you are getting into before you get into it. In fact to anyone considering such a thing, I would SUGGEST to consider just doing it on your own, film it yourself and then offer the video to a producer after the fact. Of course if you can't afford to go it alone, you could try pitching your idea to a producer and maybe get a bite.
My older brother was offered a part as the main 'bad dude' in a Mexican movie some years ago, the pay was OK but nothing to get excited over and he turned it down as he was engaged full time at Doc Rickett's Lab playing every week. Afterwards he regretted it as the female lead in the movie was a hot tamale and the 'bad dude' had several interesting scenes in the movie with her, the movie had lots of shoot-em-up action scenes too. Morale of story - don't pass up a good thing if you can find it, but as Mike has pointed out - watch out and don't leap without looking.
Coffee?