I'd like to apologize as well. I have a bad habit of not knowing when to stop talking to someone. I agree with you and several commenters about about not being able to immediately recognize trolls, although I think it's good in the long run that we are slow on the uptake rather than trigger-happy.

There is, of course, an important difference between leaving a debate unfinished and walking out on one that's a lost cause. But as you pointed out, it's hard to distinguish between the two from an inside perspective. What I'm going to try to do in the future is simply ignore people when they reuse previously refuted arguments, as this is generally a sign of dishonesty or denial.