> Don't blame the victims that the well was poisoned, blame the jerk who poisoned it.
Why are they drinking from someone else's well? Someone with "a sizeable past history of jerkdom"?
If you can check the water - nay, if you can copy the water and check it, and create an identical well from that water so that said jerk may never interfere with it again - then the "victims" have no one to blame but themselves.
If he had poisoned other people's wells you might have a point. He didn't, in the same way that poisoning the water I keep in my fridge is not an attack on anyone else. Why do you trust the water in my fridge without checking it?