The guy is driving down the road happy as a clam.
It's a nice sunny day and he's in his tank top and shorts.
Windows open, radio blasting.
A bee flies into the car, landing on the top of his right thigh and stings him.
He reacts by stomping on the brakes.
His car needs a brake job and pulls hard to the left causing the car to veer and then flip.
Or... his Karma Bank is severely over-drawn.
Gnarls.