That's really strange, because apparently I and everyone else have had no problems accessing the forum via Tor since the attack stopped.
Just to add as another testimony - I too haven't had any kind of blockages nor problems accessing the forum via Tor today. I in fact open multiple pages that I had saved regarding bitcointalk (10+) and not even in one of them did I had any kind of prompt to tell if I was a robot or not.
Usually when I had those problems I did what ranochigo suggested - especially new circuit - and it would clear, but I reckon that it may not always work.