Looks as if the material of some surface of the track is not defined properly in the tdf. But it's a bit hard to see what you exactly mean.
On Nürburgring, the cars steers out of track autonomous in 90 degrees without speed or steering the wheel, just like a mysterious force.
Maybe being on a curb you had a wheel of the ground? Even if not applying throttle, the engine still produce torque
My guess, auto spin recovery (or whatever is called) turned on. Check in the difficulty settings anyway.