The FAA report gives the position of his last radio contact as 2 miles east
of Manteca. This is right in the middle of the California Central Valley -
flat farm land, about 50' MSL that stretches uninterrupted north to south
for more than 350 miles. It is probably the longest emergency landing strip
west of the Rockies. There is no shortage of real airports either.

I would assume that either the spin was not recoverable, or the pilot simply
followed the instructions to use the BSR in the event of a spin. The real
question is how you could get into a spin from turbulence in cruise flight
in the first place. However, there were some mean thunderstorms in the area
at the time (2" of rain fell in Sacramento earlier in the day and the
weather was heading SW towards the accident area). Basically it was a mean
cold front that swept through the area about the time of the accident- and
it certainly wasn't forecast to be as wild as it turned out (wild by CA
standards that is). I would think he more than likely got caught up in some
of that convective activity.