I asked Google and they told me there was no update over the weekend.
No update? Webmaster could not believe it. They saw huge changes across many sites in terms of ranking and traffic. So what is going on?
Who knows - I do believe Google said there was no webspam update. But maybe it was something else? Remember when Hummingbird launched, they said it launched a month prior to their official announcement? I reported updates on 9/12, 9/4 and 8/24 - all of which Google denied. Those were all about a month prior to the official announcement of Hummingbird.
Maybe, just maybe, this was an update but not according to Google's terminology? I don't know.
But as far as Panda, it was definitely not a Panda update. Google said there was not an update at all, but I specifically asked about Panda.