The Mishnah in Bava Kamma 59a tells us that if Reuven sent a חרש שוטה וקטן (a person who does not understand the repercussions of his actions or under Bar Mitzva) to do a destructive action e.g handing him burning coals which he uses to destroy a field Reuven would be:
"פטור בדיני אדם וחייב בדיני שמים"
exempt in a human court, but liable in the court of Heaven.
However if Reuven sent Shimon to do a destructive act (Shimon understands what he is doing and is over Bar mitzva), Shimon would be chayav.
The Gemara in Kiddushin 42b referencing this Mishnah asks:.
Why isn't Reuven liable surely"שלוחו של אדם כמותו" ( Shimon is doing his bidding and represents Reuven)!
Then answers
"שאני התם דאין שליח לדבר עבירה דאמרינן דברי הרב ודברי תלמיד דברי מי שומעים"
i.e a person's agent is like himself doesnt apply for an aveirah, because when there is a conflict between the words of Hashem vs human being, we should obviously follow divrei Hashem
My question: I understand that the Shimon is chayav (liable) for the action for the reason mentioned above - but is Reuven completely off the hook scott-free? Would he possibly get a "פטור בדיני אדם וחייב בדיני שמים" in this case as well, even though it's not a חרש שוטה וקטן? Or some other form of penalty/ punishment?
(e.g: In American law, if someone enlisted a murder-for-hire person both would be punished- not just the one who committed the action)