I don't think it is fair to frame it so dramatically. I think you're arguing for strong diplomacy in negotiation, which I completely agree with. You could presume the original dialogue was not indicative of absolutely perfect diplomatic practices, but to say he is extremely arrogant... I would say he is justifiably confident if he has encountered relevant situations many times before and an adequate technical skill set. Either way, to pass any judgement, we're making way too many assumptions.

And ultimately, isn't this irrelevant? They are just a few general, entertaining anecdotes. I hope you don't take Dilbert or The Office seriously as well.