The Black Cats took full advantage with a 3-0 victory at the Stadium of Light.
Fletcher went to ground under Coloccini's shoulder charge and saw Madley point to the spot and produce a red card.
Magpies boss Steve McClaren was adamant the challenge was not even a foul and will appeal against the decision.
Fletcher, however, was convinced the official had got it right.
He said: "I was just looking at the ball, so I didn't know he was coming. When you're not expecting it, it's going to be a harder hit.
"He knocked me off. I think he just tried to stop me getting to the ball. It's a free-kick anywhere else, so why not a penalty?"