The lines that jumped out to me as being contradictory to the characters in the play were Mowbray and Bolingbrokes declarations for their dual. In lines 23 to 25, Mowbray stated his goal is "to prove him, in defending of myself, a traitor to my God, my king, and me; and as I truly fight, defend me heaven!" then shortly thereafter on lines 39-41, Bolingbroke says, "That he is a traitor foul and dangerous to God of heaven, King Richard, and to me; And as I truly fight, defend me heaven!"
These lines both claim the exact same thing and I think they both are similar to a logical fallacy I read about once. The logical fallacy was something about people using Hitler (or Napoleon before world war II) to define something as bad. For example they might compare Bush or Obama's (pick your poison) policy as being like that of Hitler's and since we "know" Hitler is the most evil man ever, we can consider anything related to him evil. Both of these men are using that same argument except they are appealing the all-good God, and their King who is God's representative, and then they each put themselves in that category. I'm pretty sure I didn't actually answer the real question though.