To be fair Pettitte only used HGH to recover from an injury in 2002, we aren't talking about anabolic steroids here, we're talking about a substance that was neither illegal, nor against the rules of the sport until 2005
He was using it to help rehab from an injury, not to help him pack on 20 pounds of muscle, and his use was very limited.
He was also one of the only guy's to come forward and be honest about it unlike most other players connected to PED's, who deny, deny, deny until they're trapped in a corner.