This was caused by computer error, prompted by controller error.
The U-2 was flying above 60,000', where they operate in a manner similar to VFR/OTP. When a controller took the flight plan, he entered the altitude as 600/OTP in error, instead of just 600. This confused the computer, causing it to process the flight information at all altitudes from ground to 60,000. This caused the computer to enter 'loops' and eventually crash.
Palmdale Center is using a newish ATC computer system called ERAMS. This was probably the first time the computer had seen this error (controllers can be very inventive).
I was an enroute controller for 35 years, started in Chicago before there were ANY computers. I have seen dozens, possibly hundreds of similar computer crashes, and can assure you all there is nothing sinister (other than incompetence) behind it.
thx. good post