I look at all options...
1) The money could have arrived via dredge according to evidence of what can go through the dredge, and the fact of the money being protected in the bag (possibly)
2) The flight path could be wrong and Cooper could of impacted around that area, or lost the money on the way down.
3) I don't believe a plant was involved. evidence of a debris field, money not really buried, a plant wouldn't "throw off" the investigation anymore than it already is.
4) Cooper could of jumped at the wrong time given the fact of timing vs dark, cloudy and no positive way he knew exactly where he was. McCoy kept a sharp eye on pinpointing his location with constant updates from the crew. the plane obviously crossed the river at one point, and you have money downstream from the plane?
5) The jump time is very suspect leading the jump closer to the Columbia than originally suspected. we could have a simple solution instead of making it complex? water doesn't always give up the dead. we could easily be overlooking the obvious.