Oh, Ezra. There's a moment of indecision, where Obi-Wan is still in the face of Ezra's sudden outburst. He's not necessarily caught off-guard -- Ezra's grief had been plain, both in the Force and in his general demeanor -- and Obi-Wan knew that some outpouring of emotion would likely be coming. It's a moment of uncertainty, not entirely sure of what to do.

But then the moment is over and Obi-Wan kneels in front of Ezra and puts his hands on the boy's shoulders. "You're safe here."

Not it's all right because it clearly wasn't. Not don't cry, not when Ezra's entire life had changed in an instant.