The specific cause of the problem was a bug in the HF20 code. A constant was changed that should not have been, and this caused the initial fork. Your witnesses did a fantastic job of quickly spotting the suspicious behavior and began reverting to a stable build of the Steem blockchain. This exposed another bug that resided in our fork database logic that was present due to the infrequency that this logic is activated, and which caused the minority fork to halt as well.

Thank you for staying on the top of this & keeping us updated. @SteemitBlog