This is sort of off topic, but I think it gets at the spirit behind this post.
Most people are not arguing primarily for the sake of figuring out what is right or wrong. For most people, all arguments are had within a context of a broader social interaction. About 80% of all social interactions communicate things like whether or not the people involved like each other or not, and especially who is the dominant person in the group. The remaining 20% is about the specific topic at hand, such as the topic of argument or the specific words said.
So, whenever you bring something up to someone which contradicts what they think or say, 80% of what that communicates is that you are their enemy, and that you're trying to put them down to rise up in social rank.
It can sound really primitive and dramatic when you first realize it, but if you think about survival as a group oriented animal, you can see the evolutionary psychology behind it.
As such, to be effective at communicating, you need to take that 80% social subtext into consideration. An autistic person will probably never be great at that, but I know that if an autistic person can become even just a little bit better at portraying the correct subtext, the more familiar purely analytic approach will be a lot more effective. The best\most effective debaters are good at both the emotional subtext and rational surface aspects of persuasion.