I can't help thinking somebody in BA accounts was asked to scrutiny the figures from the airport commission.
I'm still incredulous that shareholders of HAL meekly accept the premise whilst their largest customer is aghast at the figures !
More likely their largest customer is sweating at the prospect of 'Fortress Heathrow' being opened up to more competition...
The figures for the project only start to become unreasonable if you accept without question the sums bandied about by TfL (i.e. the £20bn figure for transport infrastructure), which is pretty much TfL looking to mug any handy private sector developer into funding their transport wish list.