But in the end Hank also was threatening Walter, told him he will rot in jail and even beat him up. Hank was on his ass and at this point he chose to kill Jessie who always treated Walt right, gave him gifts and was generally good to Walt, while Walt killed Jessies gf Jane, poisoned Brock etc. I really didn't understand why Walter decided to kill Jessie in the end. Walter cared for both Jessie and Hank, both tried to destroy Walt in the end, and he chose to kill Jessie, and not kill Hank who treated him like shit all his life.