The reality TV star made a blunder during the programme, commenting on two performances by a singer when he had only sung once.
According to TMZ, Abdul was spotted looking "bubbly" following "at least one martini" at an LA restaurant just four hours before the show.
Explaining her actions, the judge said: "It got very confusing. The producers come up to us in the dark and said, 'We are not going to have you guys judge after each performer, we are going to have all the performers go once, then twice and at the end critique them'."
Abdul insisted reports she was drunk were "absolutely not true".
Producers claimed yesterday that the show's credibility hadn't been damaged by Abdul's mistake.