is this something 'major' - this happens everywhere - is it just because its in London its of interest
That may be, but it can be very useful to have these incidents discussed here.
I'd never considered that the aircraft logic might think it was still on the ground and what that might do to the flight deck workload.
In these days when there is practically no pilot/atc liason and certainly no feedback from these incidents to atc, I find pprune the only place I can pick up this information.
Many thanks to SNAFU AGAIN and HAND SOLO for taking the time to respond constructively.