The incident began following Joy's rendition of Bob Marley's "Turn Your Lights Down Low."
"Megan, I really like you but I think you're in trouble. Here's the thing, it's just not the song choice for you, Bob Marley. I wanna hear Adele's 'Chasing Pavements'..." said DioGuardi before Joy's brother yelled "broken record" from the audience.
"Well, let me not be a broken record and say 'Chasing Pavement,' Adele, that part of your register was even getting irritating for the first time. There was no falsetto. You have a beautiful falsetto and you never use it," continued DioGuardi, who was this time met by a chorus of boos.
"Alright, you get up here and do it then!" yelled DioGuardi in response, which prompted a quick quip from Cowell.
"Don't fall out with our audience," he told her.
After Paula Abdul gave her own comments, Cowell took it upon himself to defend DioGuardi's earlier comments.
"The problem was is that the song was boring. It was indulgent, it was monotonous and all the things we all liked about you are disappearing," he said. "You are actually becoming indulgent, and nobody's gonna like that song and I agree with Kara. It just wasn't you, and it is all about song choice . It was just so boring."
Jackson agreed with Cowell and DioGuardi, likening Joy's performance to "watching paint dry."
However the 23-year-old divorced mother from Utah -- who began Idol's eighth season as Megan Corkrey and then switched to Megan Joy Corkrey before settling on Megan Joy, her middle name, in recent weeks -- defended her song selection after the judges' comments.
"I think that the audience was feeling it and I think that my fans were feeling it," she told Idol host Ryan Seacrest, who asked if she understood the judges' criticism.
"I understand what they're saying and I fully intend on bringing what they have envisioned because I can understand that now," she replied. "But I liked my song."
"You've been saying that every week," said Cowell, taking a not-so-subtle jab at the "broken record" comment Joy's brother had hurled at DioGuardi.
However the incident apparently didn't end there, as Us reported DioGuardi decided to confront Joy's brother during the commercial break.
At first, DioGuardi thought Joy's brother was yelling "broken record" at his sister, according to Us, however he subsequently clarified that the comment was instead meant for the Idol judge.
"I am [a broken record]? Why?" asked DioGuardi, according to Us.
Joy's brother responded by telling DioGuardi that "packaged artist" could be her "packaged phrase," according to Us, which reported DioGuardi then "stormed off with her bodyguards."
However the rookie Idol judge apparently wasn't satisfied, as Us reported she decided to confront Joy's brother again during the next commercial break.
"Can you believe what he said to me?" DioGuardi reportedly asked the people sitting around Joy's brother.