Now that fan has filed a lawsuit alleging Williams should have never been allowed to take the stage.
Carlos Castro-Lino was sitting third row from the stage during a show last week when things went from funny to serious.
"When he stepped down he started saying, 'Hey, hey, hey,"' he said.
Williams was captured on video hitting an audience member in the head with his microphone and returning to the stage.
"Excuse me, mic check," he is heard saying.
"Every time I see that video the way I see he hits me, he hits me with force like he had anger," said Castro. "Every time I see it, it just makes me mad."
Castro claims he passed out after that blow to the head and suffered a concussion.
Seattle police charged Williams with assault, but Castro has now filed a lawsuit against the comedian and Seattle Theatre Group.
"It's just really humiliating. People that don't even know me are talking about it," Castro said.
Castro's lawsuit alleges Seattle Theatre Group failed to provide adequate security for the audience.
"It should have been canceled if they knew he wasn't in good conditions to perform," he said.
The complaint alleges Williams was unable to perform a scheduled show the previous night, and the comedian had previously shown "signs of mental instability."
Seattle Theatre Group issued the following written statement: "We have shared our disappointment with Mr. Williams' behavior in a letter to our patrons. STG will respond to the lawsuit through the court system."
Williams did not show up for his court appearance on Wednesday in Seattle.
His attorney said Williams had a medical condition that kept him from traveling. As a result, the judge issued a warrant for his arrest.