That was his second run his first run was on a standard Mountain Bike and he smashed the previous world record (set by himself a couple of years earlier) by recording a speed of 101mph. His second run, on a specially modified carbon fiber bike ended in the crash. He broke several ribs and his sternum but was lucky to be alive.
He had crossed the speed sensor when the crash happened which recorded his speed at 107mph. So even though he crashed he got the record.
It has since been beat by Mark Stockl who beat it by going 130.7mph aug 2007 on snow. [ame=http://www.youtube.com/watch?v=dhAkj1UBY1c]YouTube - Markus Stöckl "serial bike downhill world record 210,4 km/h"[/ame]