How do you make a joke?

The back doors to the ambulance flew open and a man covered with blood was rushed into the emergency room.
The paramedics said he was a comedian who had been beaten up by an angry mob.
After he was handed off to the doctors, the paramedics went out for a smoke with the desk clerk.
“Let me guess,” said the clerk. “He tried to tell 9/11 jokes and the crowd got really ugly.”
“No,” said the paramedic. “He was at a dinner party hosted by the Saudi Arabian consulate.”
“So why was he attacked?”
“He refused to make 9/11 jokes.”