Do you accept that turning from a major road in to a minor doesn't give you any priority over traffic already proceeding along the minor road? I am not being funny, I'm just asking because a lot of people don't realise. The front of your car shouldn't really have been there to hit.
You weren't going overly fast, he was, but from the video, I wonder if you may have focused on what the first car was doing and not looked up the road before actually turning in to it. The Vectra and the parked cars were there to see? If you did look and saw him travelling fast, why make the turn? If you didn't look because you had an expectation that nobody would be going stupidly fast in such bad weather, understandable, but it makes you at least partly liable in my estimation.
I'm sorry but I don't see the Vectra losing his back end as a separate incident to your action. I think he brakes hard to try to avoid you, and due to the ice, this causes a skid.
From the RoSPA mindset (Yes I am a member
) every accident is usually analysed with "What could I have done better", but when on the phone to the insurance, the opposite is true, I hope me putting an alternative view gives you practice defending yourself if/when needed.