I thought about it - unconvinced that Rune has to do this if they are mafia here. Assume they are mafia - they have one other partner in the game. There are still a lot of other people that could make easier pushes on, compared to Atlas. In fact I would argue that pushing against Atlas makes more sense as town here in order to combat what he perceived as Apathy today, and the previous day.
If Drek/Juno is T/T all they have to do is jump on one of them to get further along into the game. If one of them is a wolf all they have to do is jump against the town, or go against an easier to push town to try to execute. Pushing against Atlas seems like too much of a bold move for too little gain.