I've spent thousands of hours close to the terrain in that region, and considerable time close to the terrain in the area that the crash reportedly occurred. Frequently within 15 feet to 100 feet of the terrain, and nearly always in high winds, and much of it in light aircraft, as well as large airplanes, turboprops, pistons, and turbojets.
Shears, severe to extreme turbulence, rotors, downdrafts, and updrafts can not only put an airplane into the mountain, but can separate it in flight.
Those who question Fossett's competence or his need or right to be there do so in ignorance, and should be immediately discounted as without credibility. How would they know?