This seems odd, because I wasn't having this issue a week ago. When I'm reading a thread on my Android tablet, the "Post Comment" button has disappeared. I'm still able to type in the post text box, but the button itself is gone. Drafts made on my tablet persist to when I read the forum with a different machine (also using Chrome).

"Preview" and "Save Draft" appear as links, not buttons.
For what it's worth, I don't seem to be having any problems creating this thread from the tablet.