YG did touch on the incident that sparked a cancelation of his concert on UCI ground in California. His response to the situation as a whole, and perhaps to Famous Dex directly, was rather terse. On Twitter, he filed his grievance in so many words: "Show canceled. Wack ass f*ck."
As reported, Famous Dex who was opening for YG for UCI's annual Shocktoberfest celebration is at least partially to blame for causing a stampede thereby ending the concert prematurely, before YG could ever take the stage. The eyewitness account reported in the Tweet (below), although arbitrary, seems to indicate that members of the crowd had begun jumping the guardrail before Dexter ever produced his weapon. According to the report, Famous Dex crossed the stage-crowd barrier thus inciting spectators to do the same. From there, things got super ugly, according to the same report.
After evading the mob in a white Chevrolet, Famous Dex jumped on IG live to speak his piece -- clear his name. "Don't act like it's my fault 'cause I set off a riot and a good ass time," said Famous Dex in response to the growing heat he was under via social media. As of this writing, the UCI twitter page is bereft of any mention of a riot of any kind.