Tyre mismatch would have caused that in the damp in my opinion. I hate Pirelli tyres, they are utterly sh*te in the wet and the Eagle F1s bite very well in the corners, even when it's damp and cold.
That coupled with new handling characteristics that you're not used to - recipe for disaster.
Hope you get it repaired ASAP, and when you do - sack off the Pirellis in favour of matched Eagles all round, or swap them to the front at the very least