Sad business and I sort of know how bicycle and motorcycle riders can get carried away in the thrill of nailing a windy road (downhill for cyclists) but, with age, I have realised that doing this on a shared public road is er, quite risky. I have had my scares and scars, mainly on gravel roads in KZN and Lesotho, and lost a few friends along the way and seen plaster city first hand.
I have been "surprised" (skrikked) by a breakfast run howling past me when I was puttering at 100km/hr on a dirt bike and encountered some cyclists that needed evasive action to pass safely but it is what it is.
My take: if you want to go (really) fast on a road going motorcycle, go to track days (there should be more "let off steam opportunities" I think).
Road bicycle; if knowingly sharing the road with traffic (I hardly do) it can be deadly dangerous, even being sharp isn't enough as there is always some bastid out to kill you. I'm just back from a 40minute trundle (lights front and back), mainly on surfaced roads, and there were plenty of opportunities for bad accidents, mainly cars pulling out of driveways or turning across at intersections. Makes you think when enjoying a downhill even at 50km/hr.
I really hope the cyclist heals up and the motorcyclist learns a lesson.