Another point-of-a-gun confession, like that of two episodes back –Red Sauce- that on its own would not hold up in court. This "confess or die" trick, simply means that the confession was garnered under duress, under threat of life. It therefore means that the confession itself is suspect.
Unlike the Red Sauce episode, this time at least the writers followed through with having the kid confess again at the station house, where he wasn't under any threat of life.
As well, this time it was good to see Jane explain how he came to his conclusions. It was also good earlier to see the rest of the team ask him how he did something, and even come across as fed-up or annoyed when he didn't answer, letting Jane know that they aren't simply his ready-made audience when he wants to show how smart he is.
Now all that's needed is for someone to smack the smirk off his face –fugitively of course- and let him know that they rather he save his condescending smile for the perps and not for his colleagues and friends.