In a situation this specific, it seems to me to be worthwhile to reply exactly once, in order to inform other readers. Don't expect to change the troll's opinion, but making one comment in order to prevent them from accidentally convincing other people seems worthwhile.
"I believe I said that, Doctor" -- Spock
I've created a new website for my ebook Facing the Intelligence Explosion:
This page is the dedicated discussion page for Facing the Intelligence Explosion.
If you'd like to comment on a particular chapter, please give the chapter name at top of your comment so that others can more easily understand your comment. For example: