Dunno if it's relevant or not, but we used to get the FMSs split into independant operation on the F100 from time to time.
Although it would happen anywhere, a regular place was at DPE on the descent into CDG from the UK. For any phones left on this would be their first chance of registering on the French networks.
Conclusive eveidence, no. But it was often enough to make me wonder.
