How many people have downloaded the crash video
Currently the crash video has been downloaded in excess of 200,000 times from Bodsworld, 81,286 from http://www.uponone.com

What helmet cam do you use
I currently use 2 x 21CWSHR (Sony High res CCD) one mounted via a Velcro mount to my helmet and the other on the bike.

What is better camcorder or portable DVR recorder
This choice is ultimately your own personal preference. Your choice should be based on what your intended final format is (mine is DVD).
Portable DVR recorders are designed to have the video recorded and played back on the built in LCD screen. They normally record using MPEG4 format and if you intend to convert this to dvd the quality loss can be quite substantial.
Digital camcorders must have AV-IN (analogue in) but are the best when you final format is DVD. Check out AVforums to see what camcorders are compatible.

How did his helmet come off
The helmet was the seatbelt fastener type and all we can assume was it wasn't clipped together properly.

Where did it happen
The crash was on the Keilder to Bonchester Bridge road in Northumberland

What happened in the race track videos
Video 2, my off is still a mystery to me, just put the power on a little too early I think, other people saw it and couldn't understand what happened either.

Video 3, It had been raining earlier and the track was wet, we were all on full wets all day but by dinner time the track had a dry line, so back onto Supercorsas, which are fine until you go on the wet bit and low side it