How are the grain elevators supposed to check? My understanding is that their model is more like a charity shop taking the discards of others then offering it back for cheap. They mix it all in together too I believe and won't have the funds to undergo expensive testing nor why should they? Its not their fault this new products arrived. How much testing do they do for stolens seeds currently?

I like your solution in the final paragraph but Monsanto should incur 100% of the costs. How would you deal with if mixed batches arrive as one batch?