Doesn't look like much of a centerline on that taxiway. Does BA have an Airport Moving Map installation?
Maybe a wider discussion on taxi way markings and how information is presented to pilots on aerodrome plates (and notams) will follow.
One can imagine certain factors such as poor signage, lighting and/or charts.
Maybe "someone" head down reprogramming FMC for change in SID/departure?
Distraction from the primary task of taxying safely.
These days airline crews are given far, far too many tasks to do while taxying out to the runway.
But be honest. Who hasn't looked up while taxying - and got a bit of a shock? Yes?
Sorry, that is ridiculous. If there are too many tasks while taxying you stop them or set the parking brake. All of the crew pays attention to the here and now. Taxying in an unknown area with minimal lighting (if it was well known to the crew or well lit.....) all heads are up. No exceptions.
And let me add: We all know that taxiing is a very delicate phase of flight, it happened also to me to make a mistake despite the briefing, the control signals, the comparison of the current heading with that of the airport chart.
But: is it possible that these things happen in the age of TOM TOM?
So Who’s at fault?