Ovekvam - DSC was enabled and I was in Comfort setting. This was just a cruise home after a long country journey.
SteveC - My tyres were Pirelli P7 Cinturato 195/55/16. The narrowest available for the F20. Given - the weren't brand new. Slightly worn but well within the legal limit. Insurance paid out without even a hint of questioning the tread depth of the tyres.
As you can see on the Top Gear video, it wasn't the front which let go. And this is exactly what I felt during my accident. It was the rear which just stepped out of line to the right, forcing the front of the car to the left just like in a classic drift. Except its a different thing when you drift on purpose and when you are caught by it by surprise at over 100 km/h.
I think that rear aerofoil/spoiler would probably place more downforce on the rear tyres, thus preventing them from loosing traction and stepping out of line.
Since the accident, I have another F20, but now I have a 50kg bag of cement in the boot putting some downforce on the rear axle. The car handles much better now.