There are many inherent expectations of anyone who offers to participate in an AMA. Some who agree to participate do not understand or fully understand what they are walking into, then there are those who think they are being gracious just by participating.
Hence the reactions you see. A few returning AMA guest do become quite adept at knowing what is safe to answer and how to filter chaff
I usually wait for the interesting AMAs to show up on /r/tabled before I even bother looking at them. Much cleaner way to go through them and avoid the clutter.
I think it's smart to wait a bit before replying, because there are more comments posted every minute than you can possibly read. So just let the up/down votes filter out the rubbish.
Sometimes I need more time just to write a two sentence email reply. Give Julian the time he needs.