Rolling Stone has an interview with Two Gallants, the band involved in the altercation:
RS: What exactly happened after he came onstage with you?CONTACT: Leave me a Houston or Texas media news tip | COMMENT: Click to leave your thoughts on this post here
AS: All I did was question him. I just wanted to know why. You don’t walk up to the stage of a venue that has a license to play music. We’re not the ones to blame for it. You don’t come up to us. You go to the establishment first. We were still kind of playing. He was right up in my face, and then I just questioned him the second time. This was in a matter of seconds. For a second we really ignored him and kept playing. It all happened really quickly, within like maybe 3 seconds.