Some quick comments on Ryan, from someone who is a private criminalist - ie: sometimes works for the defense.
When the defense community learns a criminalist is "in play", or considering leaving working for the state, they fast track to try and hire you. Not because they want a "liar for hire", but because they have access to someone who can accurately read the highly technical reports/notes relating to a case.
Also as incorrectly hinted in CSI:LV, the evidence doesn't speak for itself. The CSI interprets the evidence, and speaks for it. There can therefore be more than one correct interpretation of the evidence.
As far as Ryan "setting up" Nat for leaving the evidence in the HUMV, I don't buy it. When he told her about the scheduled appointment (doing her a favor), he had NO idea she would have evidence in her car. Remember she was at the original crime scene at the time (bus jacking), not at the scene where the motorcycle was found, when he told her about the appointment.
As far as telling Horatio vs telling his employer, Ryan followed procedure. He's working for the other side in the case. It would be the equivalent of someone else in the lab telling the defense about the keys if Ryan were to tell Horatio instead of the defense.
The MAIN purpose of the defense team, and criminalist, is to ensure the quality of forensic analysis (police investigation). Without an adversarial system of checks and balances, police and scientists would become complacent and sloppy.
All in all, the introduction of Ryan to the "dark side" as it is called, made this episode one of my favorites. I've always thought they need a defense CSI in these shows. Just to make sure the government employees were doing their jobs right.
Just my $0.02
