This is the cowards approach. Take the time and rebuttal properly, or don't reply at all. Just because you're "e-popular" on HN doesn't give you a free pass for weak arguments.
I agree. Saying "well, I can tell you for a fact that you are wrong, but I don't have time right now" is a very poor form of debate. Hopefully he elaborates soon, as I think he's a very intelligent poster!
A proper rebuttal would probably warrant at least something of blog post length, if not an actual essay.
If you try to make some shorter reply in this audience then it would simply be hyperanalyzed to find every little chink on the armor of the logical argument (and failing that, simply to start making emotional appeals that ignore logic completely).
It's pretty funny when the "chilling effect" applies in the opposite direction IMHO; it's something I've also struggled with IRT the Snowden Saga.