How is Caleb untrustworthy, when he did not break anyone's trust. Ann does not belong to John. Caleb has same right to pursue Ann like John. Also Caleb never lied about anything.
While John betrayed both Johns and Ann's trust. Caleb trusted him with his life and John killed him. And john lied to Ann how Caleb left her because he did not care for her.
I seriously can not understand your process of thought.