We had this discussion last time someone did it. It's not human-powered (the Battle Mountain thread is over here), but it's riding a bike at ludicrous speed with imminent risk of splatty DETH, so credit where it's due.
So this isn't about riding a bike at the highest possible speed, but about something else. (Like wreckless risk taking) Yes?
Your view of wreckless risk taking is likely to be different to someone else's. He will have considered the possibilities of splatty deth, the likely chance of success and weighed up the options. I know nothing about him but it's possible he's already used to going fast.
Some brains are better tuned to operating at high speed than others. Motorbike racers - especially the closed road Isle of Man types go even faster on narrow twisty roads where splatty deth is far more likely than on a runway where all that protective gear (same as a m/bike racer would use) would allow him to slide gradually to a halt without too many friction burns or broken bones. Some injuries are likely but I'd suggest splatty deth is actually quite remote in this case.
Also, is putting only yourself at risk wreckless? If done down my local high street where innocent bystanders are in the path of danger then, yes in my view it's wreckless, on an empty airfield where the only injuries will occur to yourself then it isn't.
Didn't Guy Martin do this same thing a few years ago? I thought he held the record or did he not succeed?