I think he made a mistake on this one. Brings to mind a line Harrison Ford used in the movie "Clear and Present Danger" when discussing how the President should react to the news that someone he was associated with was killed by members of a Colombian drug cartel. The initial inclination was to deny knowing the person, or distance himself at the very least. Harrison Ford's character suggested the exact opposite, get in front of the story, tell everyone they weren't just good friends, but GREAT friends. That way, it looks like the President has nothing to hide, and the media won't have anywhere to go with the story.
Brady should have done the same thing -- admit he told the ball boy to let some air pressure out, but say it was an honest mistake -- "I thought I could tell the difference between a legal ball and one that was too soft simply by gripping it and I made a mistake. I should have ensured that they were still fully compliant with the rules, and I apologize. I will definitely make sure this doesn't happen again."
Story over.