This is business, gentlemen's agreements happen all the time. Like it has been said, admitting to being bound to buy them would be illegal to the eyes of the lega. it's a business, thinking in terms of lies or truth is very naive.
I don't want to sound paranoid, but wouldn't admitting to a deal like that be breaking the Serie A rules? I think because of that we can't ever know if there was an agreement or not.