I'll post what I said over a year ago when this was being discussed re. the Bromsgrove derailment:
"I believe the driver of the 66 was indeed dismissed initially but then reinstated on appeal (and given a final warning about phone use).
Given the rather unprecedented and unique circumstances of that evening, plus a prior good record, I would imagine that being the main reason for a successful appeal: normally nowadays any mobile phone incidents are dealt with in a similar way to drugs/alcohol infringements: zero tolerance."