This is an interesting subject. How one would handle if it were them in the situation. One doesn't want to condone someones breaking of the law. And again you don't want to be the informer either.
Baiting has been on going for years in Wisconsin. That's what brought CWD into focus over there. In past years it sounds like you and friends did well on that same parcel of leased land. I don't think anyone's behavior changed this year from the lasts and the one before. Deer wander off one parcel of land to another all the time. Breeding, safety, & food are a few reasons that I know of. Its just natural for them to do so. The difference is. (I would be speculating some saying this.) That local neighbor knew where deer perhaps cross and move about on his land. And according to you it appears made use of that information before those same deer returned to your plot of leased land. I don't think you and friends were gypped or cheated. You fellows just got caught up in the natural ways wild animals behave. How I'd handle. I'd re-plant that food plot in front of your stand with another local seed instead. Like alfalfa or clover. Something natural to that area. Consider buying your seed from a local Grainary. Maybe next year you and partners will have better luck in harvesting your deer.
"Do not follow where the path leads, rather go where there is no path and leave a trail."