Granted the Columbia has the force to 'move' something. I dont see random bundles floating anywhere. Once soaked they would sink. The whole bag of money could have been pushed a long way while still buoyant or even bounced along the bottom if not buoyant ... then snagged until the dredging sucked the bundles apart?
I am struck by the gulf between 'natural means' and 'plant'. Tom makes it sounds like it's either one or the other, with no other options?! Cooper could have survived his jump up north then walked to Vancouver trying to get to Portland, and lost some or all of his money, or been separated of it in a struggle, or lost the whole bag or bundles while trying to jump a train .... point is, there are a million possibilities and shades of gray between 'natural means' and 'a plant'! But Tom is an all-or-nothing kind of guy. Black or white and nothing in between. Since he can't prove a natural means, well then it has to be a plant, and asparagus only!
My feelings are the money bundles remained inside the bank bag until they were "unsheathed" by the dredging process, or/and the bank bag decayed away at some point. The dredge is meant to move high volumes of sand, mud, sediment, etc., and it's conceivable that the money bundles were were sucked up with surrounding sand and encased within that sand inside the dredge pipe. Once the bundles were deposited in the dredge piles, the sand which encased them held them together, eliminating the effect of the rubber bands once they failed due to eventual decay. The bundles remained there, slowly decaying, until they were found in 1980.
Let's do a quick timeline of the money discovery:
1971-The skyjacking incident
About 3 years pass
1974-The Columbia River is dredged and dredge spoils are formed at Tina bar
About 6 years pass
1980-The money is found and Dr. Palmer investigates and creates his report
About 19 years pass
2009-The Citizen Sleuths re-analyze Tina Bar and come up with their own conclusions
I've already explained my opinion that Tom Kaye is a very bright guy who sometimes lacks the common sense to interpret information in a practical way. The "Cooper's body snagged on a freighter propeller and moved upstream" scenario is one example of that which comes to mind, which leads us to the theory of a "plant". This theory is used to explain the discrepancy in the timeline of when the money was deposited in the bar and the results of the rubber-band test. The problem is when we open ourselves the theories like this, based on possible misinterpretation of evidence, then we open ourselves to all kinds of wacko ideas. Next thing we know, we are looking for a suspect wearing platform shoes, contacts and a strap-on, digging holes and burying money in a river bank in 1979. Possible? Maybe. Probable? Highly unlikely.