The director had just dropped his daughter off at school and decided to check out Musso & Frank Grill in Hollywood, because he was planning to shoot at the fabled restaurant the next day, but when he arrived he found a dying man and then became caught up in a murder investigation.

"When I came into the parking lot somebody had been stabbed," he tells WENN. "There was a guy holding the wound and screaming for help. I got out of the car because there was no one else there. He was all alone.

"I hurried over to this poor man who was lying on the ground and blood was gushing out. I had my power blanket on and I took it off because he needed something to hold the wound down. I gave it to him to hold the pressure.

"Unfortunately the ambulance arrived too late and he died, so then it became a murder scene and we weren't allowed to leave, and I was basically shooting the film in the (San Fernando) Valley. I was like, 'How am I gonna do this because the insurance company certainly wasn't going to care if I'm stuck in a murder crime scene!'

The filmmaker spent hours talking to police while crew members were frantically trying to get hold of him for instructions on how to set up for the day miles away.

"I was waiting around trying to get out of the place while they were busy setting up the set...," he adds. "I was standing around with all the policemen walking around and reporting and everyone had to answer questions."

And that's when inspiration struck: "I suddenly got a really cool idea; that idea changed the film. Even though it was such a horrifying situation, I'd never seen anyone die before; it gave me one of the best ideas for the movie!"