Classic problem with ground effect cars. at that speed the side on nudge lifted the car allowing air entering under the front to "detach" the ground effect from the car making it go airborne.
Coincidentally, that is what worries me about the design of the Delta Wing car as it could have an accident like that all by itself just by taking a kerb too hard or clouting an object on the track - especially as we now know that the weight distribution has been designed to have as much of the weight rearward over the back wheels.
Oh, well, back to the race.