The actor admitted that he is proud to have backed the show's winner Jodie Prenger from the start, while his fellow judges Andrew Lloyd Webber and Cameron Macintosh wanted eventual runner-up Jessie Buckley to land the role of Nancy.
"It's difficult because you are working with these great geniuses of musical theatre, and, obviously, because I'd come up through that route, there was an aura there," Barrowman told the Daily Mail.
"But we clashed over the eventual winner. They thought they were right, rooting for Jessie. Andrew even said, 'Jessie is Nancy', but I knew that they were wrong. They were out of touch. For a while, it did feel uncomfortable to be challenging them. There was still that sense that they were thinking, 'Get back in line, boy. Your job is to make us money.'"
He added: "Maybe I am more in tune with what the public want than they are. I'm not being arrogant when I say that. I'm just being truthful."
I'd Do Anything searched for stars of a new West End version of Oliver! earlier this year. Prenger will make her debut as Nancy in December.