Agree in general with your comments.
The thing that makes me dubious about the “terrorist missile” is that there was only one.
Hard to imagine they would stop there. It’s not like they had access to the only functional manpad in the world.
There’s been all sorts of one-off terrorist attacks. The shoe bomber. The underwear bomber. 9-11 even. They tend to go with what works and gets them press. But we’ve countered the things that worked and made them harder. So 9-11 hasn’t happened again... And other attacks have been stopped.