Walsh was the final judge to select who he wanted to send home out of the bottom two - Carolynne Poole and Rylan Clark. After much deliberation, Walsh stated clearly that he wanted to save Poole.
However, O'Leary insisted that Walsh had to state who he wanted to "send home" and not just who he wanted to stay in the competition.
O'Leary's probing seemingly caused Walsh to change his mind and the Irish judge stated that he wanted to send the show "to deadlock" and the public vote. Walsh never actually stated who he wanted to "send home", but O'Leary was willing to accept his answer of taking it to deadlock.
Commenting on his changed stance on the show's rules during the finale, O'Leary said on Twitter: "Weird show. For those asking I have ask who the judges are sending home, not save. Straight question. Been like that's for 9 years (sic)!"
He later described the incident to fellow TV presenter Phillip Schofield as an "utter nightmare".
Schofield commented: "Well done [Dermot]. I'd have thumped Louis! What a fiasco!"
Poole's mentor Gary Barlow stormed off the ITV1 show after the final result was announced.
