Walsh decided not to appear on the show this weekend because of Stephen Gately's funeral, but spoke to the contestants on the telephone on The Xtra Factor.
"I never want to watch the show at home again," he joked. "I've been shouting at the TV all night."
Walsh added that he agreed with tonight's result and would have saved Rachel Adedeji, who survived the sing-off for the second week in a row tonight. Rikki Loney became the second person to be eliminated from the programme.
"I would have saved Rachel as I don't think we've seen the best of her yet," he explained. "I'm sorry about Rikki, and Rachel, pick yourself up. You can do it."
Walsh will return to The X Factor on Saturday's show, at 8pm on ITV1.