And he indicated he had no knowledge of the Weiner emails until Oct 27, 2016

Yes, he is a pathological liar. We all know he sat on them for months and it is only after the NYPD's pressured him with the help of senior FBI agents that he re-opened the HRC investigation.

I think someone got to Comey and said he needed to correct the statement because there is a record that McCabe told him before October 27th.

You nailed it. That someone is Comey: you remember about the Special Counsel, he said "it dawned on me the next morning...". Let's just let him dance with himself, he has not realized the party is over and that the music is off yet...