You can't kill Jack, and you can't execute him; you can't kill the monkey. Both passives are based on the idea that such situations resolve themselves, I believe.
For example, there are 3 Mafia members left against both Jacks. In this case, the Mafia wins, and the monkey wins with them. Or there are 2 Mafia members left against both Jacks. Then, executing a Mafia member is impossible. At night, Jack is killed, and no matter what the monkey does, the Mafia wins, and the monkey wins with them.
However, if executing the Mafia or killing them at night is still possible, they will have to wait before claiming victory.
In any case, that's how it has always been.
Если где-то чего-то убудет, то в другом месте добавится.
(Закон сохранения).