Jason Easley noted. "The really priceless moment is happening behind Romney, as Paul Ryan realizes what Romney said, and tries his very best to maintain his smile. Ryan’s face transformed into a pained expression, as Romney accidentally let loose with a bit of truth."

Within hours of the campaign event, Romney's team was walking back the former governor's statement.

"President Obama has raised taxes on millions of middle-class Americans during his first term in office," spokesperson Amanda Henneberg said in a statement to ABC News. "Governor Romney was clearly communicating about an additional tax increase President Obama is proposing on American small businesses that will jeopardize over 700,000 jobs. Mitt Romney and Paul Ryan will stop the President’s tax increases, create 12 million new jobs, and turn our economy around."

Earlier this year, a Washington Post fact check awarded the Romney campaign "Two Pinocchios" for claiming that the president "has already raised taxes on millions of Americans."

(h/t: Think Progress)