Well, whatever happened to Jacob has happened some time ago, so if someone was waiting for him to get desperate enough to go on a rampage, they were disappointed.

Jacob is a very naturally calm person and has a lot of survival experience. He’s been able to trap food on occasion (or steal cows), and certainly hasn’t come close to the point of a rampage, even after getting shot up and threatened by Dean. Which Sam and Dean know now, so it went unmentioned.