Cook and the City delegation flew home from Milan on Monday night having failed to land the former world player of the year from AC Milan.
City feel Milan simply 'bottled it,' becoming suddenly aware of the scale of unrest the decision would cause among the Rossoneri.
Cook claimed: "We truly believe Kaka is a humanitarian of the highest order.
"We would have put resources there to help build his foundation and send a message to global football about what great players can do.
"Kaka has the capability to be the next global ambassador for the game.
"But his father (Bosco Leite) just wanted an offer. He did not want to sit and talk about the rest of the stuff.
"He used the term 'it is not just about money'. It's ironic that it was."
The presence of three City lawyers at the talks surrounding the Brazilian's future emphasised the complexity of what was being proposed.
Cook estimates Kaka has 20 personal sponsorship deals, all tied in to his commitment to AC Milan. City knew, if agreement could be reached with the player and his club, those individual deals would all require negotiation.
Either the transfer just became too complicated or Leite was not prepared for the groundwork Cook and his team had done.
Cook explained: "It was just too sophisticated. Bosco does not have a lawyer so when we asked whether we could see the contracts to know what we were dealing with, he just said 'show me the offer'. It was very frustrating."