A slide here, a lock up there ... as you mention happens to *every* driver occasionally. What separates that incident from a learning experience to an expensive mistake is often luck -- an unfortunately placed wall, an off-camber road, mechanical faiure, oil deposit ... you name it. A professional driver with a zero-accident tally is a worthless driver ... either non-existant, or completely non-competitive due to not being able to push the car. Pro drivers are NOT paid to avoid all mistakes, they're paid to eliminate them as much as *humanly* possible. All airline pilots, test pilots or not, will occasionally make mistakes -- but airplanes have many levels of redundancy so typically no one mistake causes a crash; it's usually only a multiple level cascade of failures that causes crashes.