"My favorite 40-yard-dash story involves Deion Sanders’ run in 1989. Back before the Combine was televised or even all that much covered by the media, Sanders reportedly showed up to the combine late and did just one drill — and only once. As the story goes, Sanders ran a 4.29 in the 40, then jogged right into the Hoosier Dome tunnel and out the building. Without breaking stride, he hopped into a limousine and took a trip to the airport, where he boarded a plane and flew home"
This is all I have found. Hope someone can find a video.