Who Killed Xavier on "The Afterparty"? 6 Theories

Brett's (Ike Barinholtz) main motive for going after Xavier is the fact that Xavier is going after Brett's ex-wife, Zoe (Zoe Chao). Xavier makes it clear to Brett that he's going to pursue Zoe at the reunion, and Brett threatens Xavier in the bathroom. They also seemingly get into a confrontation at Xavier's house soon before Xavier falls to his death. It could be that Brett's rage over Xavier pursuing Zoe got the best of him.