Noted Rationalist responds to a question about a first strike scenario with "I need to think about it" instead of "of course we'd launch the missiles, are you kidding?" and everyone here seems to think this is somehow unbelievable.

You're still dancing around the point. Person A said X; person B said not X; we have no concrete evidence either way. Person A is an anonymous representative of a group that has no norms against dishonesty, an obvious motive to falsely claim X, and a track record of telling frequent, shameless lies. X doesn't need to be 'unbelievable' for me to ask, again, what positive reason do you have for believing it?