I've applauded the NFL for implementing a stiffer league conduct policy and taking a more aggressive stance on repeat offenders and also for included additional education and treatment measures in that conduct policy, keeping it from being a strictly punitive approach to the problem. That's why the leaked info from the combine interviews is so frustrating; it completely undermines any attempts to conduct policy focused on education and prevention as opposed something that's simply a harsher policing effort.
I don't' know who leaked the information about Okoye et al smoking pot: a rival agent, teams hoping to lower their draft status or some gossip among the NFL's office workers. It doesn't matter. The beauty of the candid interview is that players feel free to be open and thus can express a genuine interest in putting those things behind them as they enter the NFL. As long as you're clean for a drug test, you don't have to admit shit about your past, and can have coaches and the public find out about when your "friend's" crack pipe falls out of your car or you get arrested in a strip club. Admission of indiscretions, either as prospects or veterans, is the first step in preventing the kind of off-field behavior the NFL wants so badly to prevent. When something like this happens, it violates the underlying principle of trust that forms the foundation of a policy agreement, and removes the prevention aspect of that policy as players are forced to keep stuff on the down low for fear of being punished and ultimately having their contract value take a hit.