Despite a prior Washington Post article, the Accident Investigation report released by the Air Force indicates that the reason for the F-22A crash in March was the affects of the high-g environment.  While he did not G-LOC, the report basically says that he was trying very hard not to and he was only partially successful.

This mishap was caused by the [pilot’s] adverse physiological reaction to high acceleration forces and subsequent loss of situational awareness…The [pilot] channelized his attention to fight off the effects of high g-forces…[and] entered an extreme nose down, high-speed attitude from which safe recovery was not possible…

The Accident Investigation Board report can be read here (pdf) in its entirety.  Other sites have translated this accident as being caused by “A-LOC” or by “pilot error.”