and having known the man who was responsible for the (govt) BAA who ran the system - I have some guesses as to what went wrong
Aren't we talking about a NATS system here? It's not immediately obvious how or where BAA would have been involved.
Incidentally, it's being suggested on the ATC forum that the system failure may be not unconnected to this NOTAM:
E)
AT 0100 ON 07 DEC 2013 SCOTTISH AIR TRAFFIC CONTROL CENTRE MILITARY(SCOTTISH MIL)(SCATCC(MIL)) WILL TRANSITION TO SWANWICK AND ASSUME THE TITLE LONDON AIR TRAFFFIC CONTROL CENTRE MILITARY (LONDON MIL)(LATCC(MIL)) NORTH, THERE WILL BE NO CHANGES TO SERVICE PROVISION ARRANGEMENTS OR INITIAL CONTACT FREQ. ALL LATCC(MIL) SECTORS WILL ASSUME THE VOICE CALL SIGN 'SWANWICK MILITARY'. A SINGLE UK FLIGHT PLAN ADDRESS, EGZYOATT WILL BE USED FOR ALL OPERATIONAL AIR TRAFFIC FLIGHT PLANS.
LATCC(MIL) NORTH CTC DETAILS:
E-MAIL: LATCCMILNORTHSUP(AT)NATS.CO.UK FAX: 01489 612942. TEL - SUPERVISOR /AIR TRAFFIC OPERATIONAL TEL NETWORK (ATOTN): 7 590 5430 / MIL: 95586-5430 / CIV: 02380 401509. ASSISTANT SUPERVISOR / ATOTN: 7 590 5431 / MIL: 95586-5431 / CIV: 02380 401515. OPERATIONS ASSISTANT CIV: 01489 612944