This is contradicted by the evidence..
The rubber bands crumbled when the packets were picked up and the money was tested for soil/sand.. It was only Columbia River sand. Shards were also present in the sand. Plus, the money was exposed to the River in spring/early summer.
So, the money was buried for maybe 2-9 years. Not a short time. Palmer concluded the money was buried within a few years of the find..
The recent burial plant find idea just doesn't work.