Did the power come back?
Mine used to do this when driving on a motorway/dual carriageway at about 60-70mph - put your foot down and 'pop' power gone, like limp mode, no lights on dash and power would come back after 10-20 seconds.
Sorted now (via removing map and adding a dash of REVO) - car was running far too rich and requesting too much for the fuel pump to handle at a certain rpm, so it was cutting.
What map is your car running?