In my experience, there are those who have very strong ontological biases, but they don't think they have biases, they believe that their views are logically derived ways of looking at the world. What I do is show that they are not logically derived, but rather they are a bias. Now, some people, are rather content with accepting that they have a bias and have no problem with my argument. Others, however, depend on their view being right so that they can preach their ontological biases to others as knowledge. Those people, are more likely to have a problem with me.
Take Luis, for example, his argument boiled down to not being able to make his argument a logical one (i.e., stating premises, etc), because he said that I was rigging the game by doing so. Well, I didn't invent the standards of logic. Simply because his extreme internalism fails because of utilizing metaphysical-stated premises, doesn't mean that Luis is wrong, but it does mean that he is arguing on unconvincing grounds (i.e., implausible grounds as Dummett had said about such an extreme internalist position). If we start accepting logic with hidden premises that contradict itself, then where will that take us? Now, for Luis this is not acceptable because he wants all to buy into his form of agnosticism (there are, of course, much more sophisticated and philosophically acceptable forms of agnosticism), but he wants us to buy into it because he believes that his bias is the best argument. By showing that it is not since he cannot demonstrate his premises, I became the 'bad guy' (or stupid guy) or whatever. However, the real frustration being exhibited is because the argument I gave pinned him down to the point of being unable to respond (e.g., how does he react to post-modernism, etc). Luis became irrate when my 'obtuseness' bothered him to the point of anger. Someone who is obtuse can be shown to be wrong by showing that they contrad themselves or at least brought to a point to where they cannot meet a reasonable request (e.g., show all of their premises). It was Luis who came to that point, and not I. In my view, that demonstrates that Luis' frustration came from him being wrong (or at least not framing a logical argument), and not from any soul-searching needed on my part. If anything, I did search my 'soul' and found reasonable answers to the ones that Luis is biased against.
We've had many such frustrating issues ourselves, and I am confident that if we both continue to discuss issues that we will in the future have such frustrating times again (right now, we are friends) :-). I think these situations can be avoided simply by pulling back from the emotions contained in an argument. For example, I've had a number of heated discussions with Paul and Mario, but I can't think of one time where we pissed each other off to the point that we insulted the other's intelligence. In these cases, emotions have been set aside and only the issues are discussed (not someone's ignorance, etc).
If we continue such discussions in the future, I hope that you will see that there is nothing personal in these discussions, we are just going at it like I did many times with Paul and Mario which is a normal enjoyable discussion. If I do piss you off, we can always agree to disagree. I try not to gloat, but sometimes I do want to stress that I successfully made my point so that there is no misunderstanding.
Warm regards, Harv