It seems that every few hours some more information (amongst misinformation and speculation) comes out about the events leading up to the tragedy.

This latest BBC report says that Mark McKee was acting for Nantes in the transfer negotiations - I previously understood he was a broker or middleman for his father's agency bringing Cardiff and Nantes together.

https://www.bbc.co.uk/sport/football/47013474

If that is the case, and Mark McKee made the initial arrangements for the flights (via David Henderson whose role and movements are another story) to and from Nantes, would he still be regarded as an agent for Nantes when making flight arrangements on the back of the transfer deal? I assume his relationship with Nantes ended when the contract was signed (unless he is on their payroll) but maybe not. It may explain why Cardiff has reportedly frozen payments to Nantes whilst they complete the internal club investigation.