His mention of the killing, while seemingly sincere, still felt like a kiss-off.
But it's not surprising. Denial is, far too often, the Facebook way.
Remember just after the presidential election when Zuckerberg shrugged off the importance of the hyperpartisan lies in the form of news stories — like Pope Francis supposedly endorsing Donald Trump?
"Personally I think the idea that fake news on Facebook, which is a very small amount of the content, influenced the election in any way — I think is a pretty crazy idea."
In time, he changed his mind about that, and Facebook, to its credit, has made some significant moves to flag, limit and remove financial incentives for lies and misinformation that spread like a disastrous oil spill during the campaign.
But Facebook still hasn't come to terms with what it really is — a media company where people get their news and which, especially because of the year-old Facebook Live, generates news content. Since it began, rape, a horrible attack on a disabled person, and more than one suicide has been live-streamed.
"The crux of this is what is Facebook's true nature: a technology that enables anyone to publish anything? Or a self-regulating media company with enforced standards?" Emily Bell, director of the Tow Center for digital journalism at Columbia University, told me Monday evening.
Facebook's answer became clear Tuesday morning.
With its nearly 2 billion monthly active users and more than $10 billion in annual profits, Facebook is better at making money and capturing eyeballs than at owning its equally huge power and responsibilities.
David Clinch, global news editor of the verification site Storyful, put it this way: "They have to take this issue very seriously and deal with it urgently, or they will surely face more calls for Facebook Live to be put on hold until far more robust controls are put in place."
So far, that's not happening.
In recent months, Facebook has gone out of its way to avoid acknowledging the obvious: It is a media company, not simply a platform its billion-plus users to share their lives with family and friends.
But there are, of course, business reasons not to accept that. As soon as Facebook acknowledges that it is a publisher and not a platform, it may open itself up to lawsuits that could cut into profits fast.
Better, the thinking apparently goes, to stress technological advances and the ability to connect the whole world with virtual reality, baby pictures and exploding watermelons.