LAS VEGAS —

David Copperfield told a Nevada jury it would be his fault if an audience participant got hurt because of something he did wrong during an illusion.

But the magician didn’t acknowledge responsibility for a British tourist’s injury, and testified Wednesday he never even knew until he was sued a year later that the man claimed he was badly hurt while taking part in a signature Copperfield illusion.

Gavin Cox’s lawyer, Benedict Morelli, clashed with Copperfield about whether Copperfield noticed what Morelli called “construction dust” in an MGM Grand resort alley near where Cox fell.

Cox claims negligence led to his fall while he and about a dozen other audience members who seemed to have vanished onstage were hustled outdoors and back indoors to reappear in the theater.

Jurors on Tuesday got a rare behind-the-scenes look at Copperfield’s disappearing act.

The magician’s friend and executive producer, Chris Kenner, revealed to jurors the mystery behind a signature Copperfield illusion that appeared to make about a dozen audience members vanish together onstage.

Practiced stagehands with flashlights hurried randomly chosen participants through dark curtains, down unfamiliar passageways, around corners, outdoors, indoors and through an MGM Grand resort kitchen in time to re-enter the back of the theater…