Revealing mistake: At the river to cross over to Mt Weather, the vine used to swing across the river is just a standard rope, camouflaged. You can see it best when Finn recovers it after Jasper has jumped.
Kane: Peace with the grounders is the only way we'll survive. Abby: Oh, I don't think they know what 'peace' is. Kane: The Commander does. Abby: She's a child. They're being led by a child. Kane: So are we.