Airportgate: Has Cullen Lied Again? Or Did He just Misread His Briefing Papers?

On re-reading the Treasury advice to Cullen on the proposed Canadian investment in Auckland Airport we see that Treasury advised that a policy setting a 49% limit on foreign control would be preferable to what the Government was proposing. Hang on, isn't that what John Key proposed? But didn't Cullen tell us that the proposed National policy was going to breach international commitments? And don't we now know that the Government's policy has, according to Treasury, breached international commitments?