The Sun claims the Black Eyed Peas frontman amused himself during a 'boring' Blind Audition by drawing a smiley face.
However, when he went to erase the doodle, he pressed his buzzer and activated his chair by mistake.
"Will was mortified as he came face-to-face with the singer – he couldn’t have been less interested," a source explained.
"He tried to style it out by saying a ghost had pressed the button and even referenced the Patrick Swayze film as he dug a deeper hole for himself."
The other coaches Tom Jones, Jennifer Hudson and Gavin Rossdale failed to turn - meaning the act automatically joined Will's team.
It was a stroke of luck for the mystery contestant, as Will decided not to protest the error.
"Will then held his hands up and admitted he didn’t mean to turn around, but would stand by his mistake," the mole added.
“It was a bittersweet victory for the poor guy."
Will has been careless with his button before. During the last series, he admitted "slipping" for contestant Alaric Green - but Ricky Wilson also turned, and Alaric chose to join his team.
The Voice is moving to ITV next year, and bosses have already made a simple but cruel format change. Now auditionees who are snubbed by all four judges will not even get to meet them.
Filming of the Blind Auditions recently wrapped, with the new series set to hit our screens in January.