Thank you all for your comments, hopefully by posting the information I did some people will avoid getting hurt, be that emotionally or physically.
Obviously my description of what happened has provoked some conversations and, unintentionally, maybe I didn't describe everything in perfect detail that allowed all the theorists room for conjecture.
First thing, the motorcyclist couldn't have done anything to avoid the collision. There is no suggestion his speed or positioning on the road was to blame. The topography of the road at that point meant he had between 1 and 2 seconds to react and take avoiding action.
On my speed, I lost control on the left hand part of a right/left combination of bends. The angle of the bends means I couldn't have approached or attempted to take them at any more than 65-70mph. What was my speed as I entered the bend? I don't know. I do know on the straight sections preceeding those bends I had been going faster than that. According to the Collision Investigation Unit report, they were not able to calculate a speed, as all four wheels had continued to rotate throughout.
Why did the car let go? That's a question I've asked myself many times. But the point is, I shouldn't have been going so fast as to reach that limit on the road.
To put my driving experience at the time into context, I was on paper fairly well trained. I'd been doing 65,000 miles a year professionally, without problem, I'd done various defensive/fast road driving courses (mostly using ex-Class 1 Police instructors), had a decent chunk of track time, an MSA race licence, done autotests and wet skid pan training (at Durham Police HQ), many trackdays (including in the Integra I went on to crash) and so on.
Maybe that was part of the problem? I had built up this opinion of my driving that I was never going to have a big accident. I was so complacent and, worse than that, I was being complacent with other people's lives.
Finally- my position on pleading guilty (or not). I was interviewed by the roadside by an officer, during which I fully admitted guilt. Three months later, I was first interviewed under caution, then once again in the September. That arrogance didn't just disappear the moment I clambered out of the car, it took time to sink in what I'd done and how I was responsible.
My first instinct, at first interview, was to deny I'd been driving dangerously. I didn't believe I had- it was arrogance and a warped thought process. Even at the second interview, I was still not fully open to the truth of it.
Finally, in December, I was summonsed to Magistrates for a plea hearing. At that hearing I pleaded Not Guilty, because only moments before the CPS handed the evidence bundle. Whilst it would have been morally more upstanding, it would have been legally naive to plead guilty without first seeing the evidence against me. I wasn't the kind of person used to dealing with the Courts or solicitors, so I stuck to the advice I was given at the time.
As soon as the case committed to Crown, and I had the first plea hearing, I pleaded guilty- having seen the evidence, assessed how I felt and taken legal advice. Considering I did have a significant other, and family to consider, would I have willingly gone to prison? No. I'm not a big enough man to pretend I would. Had I had a chance of staying with them, rather than putting them through hell, I would have taken that option. I think most people, even the decent ones, would have done the same.
So why did I put all this information in the public domain? It was a simple thought process- I ruined the lives of a lot of people by my driving. Not just the motorcyclist, but his whole family and friend network. And the life of my other half, and our families who had to deal with this. There were no winners, just losers. The only positive I could bring out of the whole thing is to share the experience, so maybe some other people don't have to go through it.
Thank you for reading.
Dan