It's an everybody thing. Could you send a screenshot where you expect there to be a comment? Also browser / OS would be useful if the issue still persists.
EDIT: Looks like this is broken on Tapatalk. I filed a support ticket with Tapatalk, hopefully they fix the issue on their end.
Hi David, I am using Firefox, on OSX 10.7.5. Here is a screen shot. I am able to reply, but you commented within a reply, and I don't see a way to do that.