I've always been a fan of Safe's theory, that there's no possible way the money could have gotten there thru any natural means. The money was moved. Chards in other places or not, the only known fact from Tina Bar is the three bundles were found in relatively close proximity to each other if not on top of one another. The fact that the rubber bands were still in tact supports that it wasn't there the entire time or even since the dredge, in fact from the Slueths work one could say it wasn't there for more than a year. If it wasn't moved the jump time and flight path would have to be significantly off and one would have to explain how the rubber bands didn't disintegrate completely.
One thing that could have happened, and I don't think I've heard anyone talk about this, what if little Brian's parents found the money elsewhere, and after some period of time, days or longer, decided the money was worthless in it's current form and if they turned it in, they wouldn't get anything for it, perhaps they felt their chances of getting some of the money replaced for usable $$$ was if a kid found it, buried it there and told little Brian to go build a fire there. I know I read a news report of the day where Brian's mom is talking about removing the rubber bands (breaking them off) and trying to separate and wash the money or something. We know they had it for some period of time before they reported it (and I'm NOT saying there's any wrongdoing here on the part of the Ingrams, finding money and deciding what to do with it later is a natural, normal human response).
Does anybody know the Ingrams whereabouts in the days or weeks preceding when they reported it, was that ever investigated? Pure conjecture, for sure, but unexplored conjecture which is rare in Cooperland. The biggest issue with this theory is, what motivation is there on the part of the Ingrams to not report the real find location? The most logical, is the simplest, Tina Bar was an easy location to get at, perhaps returning to the "real" location would have been a PITA, and not knowing they were Cooper bills, who really cares "where" it was found. Once finding the vast implications of the bills and their origin, changing the story would have meant massive media and public backlash towards the Ingrams.
Just a theory, they are a dime a dozen it seems.