We may decide that he is a hypocrite and a fraud. This story teaches us that a surrender to temptation does not serve as a sweeping indictment. One failure, or even many, do not define a person. Just as God takes Jacob's deceit in context and proportion, so should we. The mitzvah of rebuking our fellow Jew requires, in addition to caring and involvement, the qualities of patience and prudence.
Timing is crucial.
God's paradigm with Jacob offers us latitude, and allows us a wide range of considerations, in determining how to most effectively use the process of rebuke to facilitate change. One does not exclude the other nor come at the expense of the other. Imitatio Dei means that even as we criticize unethical behavior we stay compassionate towards the person. That somebody as great as Jacob can defraud his father, and then be in denial about it, speaks volumes about our ability for self-deception. That this can happen to a prophet who is the father of our people is a humbling thought.