I really don't think there's a way they can lump you with the blame/having to pay for the damage.
We've all got evidence that you weren't driving too fast for the corner. If you had been driving too fast, you would have ended up in the hedge. The pictures show exactly what happened, and where your wheel scraped the curb.
The only way this could have happened was through a mechanical failure, i.e. ball joint. Everyone agreed that it sounds like the ball joint failed before you hit the curb, and that's what caused the loss of steering.
I'm sure everyone who saw the accident would only be too happy to provide evidence to help you. Feel free to use my pictures, and e-mail me if you want the full size originals (with EXIF data).
Don't worry Gilly, us OcUKers will help you sort it out!