Had it recently with another BA in Nice who was blocking the runway ahead of me, by liningup in slow-Mo. Slower then parking on stand. Didn't trad Back t/o clearance 3 times, then was blaming a technical problem, which can happen. After which another minute of conpleting checks followed.
This seems to happen regularly with BA as I have heard And experienced behind them!
Maybe its cultural, where their acars loadsheets make it seem "normal" to not be ready while blocking a runway or holdingpoint.