Maybe that pilot who wrote the article may have made up the number or accidentally revealed the real number.
In the article: I heard the click of Walter’s mike button in the rear seat. In his most innocent voice, Walter startled the controller by asking for a ground speed check from 81,000 feet, clearly above controlled airspace. In a cool, professional voice, the controller replied, ‘ Aspen 20, I show you at 1,982 knots on the ground.
1,982 knots = 2280.85 still a bit faster then official numbers.