The clip I saw on Twitter looked staged. EDIT: The 1st clip I saw must've been a censored version that aired in the U.S., because I just saw uncensored version of the clip from the Japan broadcast & Will Smith reaction afterwards seems real.
The Academy Condemns Will Smith’s Actions, Opens Formal Review Per a statement from the Academy of Motion Picture Arts and Sciences issued Monday: “The Academy condemns the actions of Mr. Smith at last night’s show. We have officially started a formal review around the incident and will explore further action and consequences in accordance with our Bylaws, Standards of Conduct, and California law.” The matter is likely to be more fully addressed at the next full meeting of the Academy’s board of governors. The first post-Oscars board meeting always features a post-mortem of the ceremony and addresses issues that arose during the ceremony. [viaTheHollywoodReporter]