'He made an ambitious song choice this week and it did him in,' one expert says.By Gil Kaufman Tim Urban Photo: Frank Micelotta/ Getty Images There are worse ways to fail than being too ambitious or too nice. But for booted "American Idol" finalist "Teflon" Tim Urban, it was a combination of his sunny persona and decision to stretch outside his comfort zone that contributed to his undoing on the show. After Urban was eliminated during Wednesday night's "Idol Gives Back" special, some "Idol" experts said they weren't shocked — and might have been a bit relieved. "Tim Urban was the little engine that could ...