Max speed must be the most pointless statistic in cycling. Especially when the device recording it is suspect.
I've done this same descent and I'm failing to see the part where he hits crazy speed.
I think I did the descent reasonably fast with a 53-11T and didn't have a tailwind nor a rider or vehicle to draft. It wasn't anything special and I got a little lost at one point. Because of this thread I went back to check my speed and turns out it was the 14th fastest descent out of 1988 riders on Strava - I guess I wasn't too lazy recovering from the climb.
My max was a pedestrian 72.7 kph. http://vimeo.com/24482370
So yes I would ride as fast as possible down Ventoux on a 5.2kg bike
But that's nowhere near 131kph because that kind of speed is not possible. Ventoux isn't very technical, but it isn't a very fast descent either. I'd actually say that it's rather bland and a bit boring compared with some other big mountain descents.