Re: Ex post vs ex ante
That'll be because the boss of Openreach (Mike McTighe) also served on the board of Ofcom.
So he'll know perfectly how to avoid Ofcom intervention. And because Openreach is completely owned and funded by BT....well, obviously you don't annoy your funding source.
All of that is simple public records:
https://newsroom.bt.com/mike-mctighe-to-be-first-openreach-chairman/
https://www.openreach.com/about/how-were-led
Still. Nothing to see here. All legal and above board.
Now excuse me, I've got some bridges to sell.