In February 2004 — when phones weren’t smart, Twitter didn’t exist, The Facebook was days away from birth, LeBron James was still a teenager and Donald Trump was still a Democrat with a reality show — Janet Jackson had a nightmare unfold, in the space of a second, as she headlined the MTV-produced halftime show of Super Bowl XXXVIII. Before a crowd of over 71,000 and 90 million more watching on TV, Ms. Jackson performed a medley of her hits across three decades. She was then joined for a finale by a bearded yet still baby-faced Justin Timberlake to perform “Rock Your Body,” a catchy, dance-inducing number from his solo debut.

The song, which threw the crowd into a happy frenzy, briefly became a duet. Then, in a cinematic shock — as the duo spun apart for what was meant as a final “costume reveal” in the choreography — Mr. Timberlake ripped off a portion of Ms. Jackson’s top, exposing her right breast on live television, just after he’d delivered the song’s last line: “Bet I’ll have you naked by the end of this song.”

Image A nightmare about to unfold. Janet Jackson and Justin Timberlake at Super Bowl XXXVIII. Credit... Jeff Kravitz/FilmMagic, via Getty Images

By the time heads quit spinning, “wardrobe malfunction” had been coined, and what was meant to be a crowning moment for Ms. Jackson was reduced to a meme. They both said it was an accident. But conspiracy theories abounded, and still do.

Parent groups, major advertisers (their parent companies ) and the White House all condemned the incident. CBS was handed a fine by the Federal Communications Commission for indecency, which was ultimately voided. And Mr. Timberlake — who, accidentally or not, did the ripping — largely avoided public rebuke.