a tad harsh?
Yep harsh, but chances are very likely he appealed to a higher court--if he didn't then he is a idiot. I think he did have a attorney with him (Possibly a Public Defender).
Also, he is 18 yrs old, and may even have a juvi record. You have a situation here, where he knew what he was doing and the punishment for the crime. He possibly was doing for the rush, and many 18 yr oldsters don't think that now, "I'm an adult---for everything" and that they don't have to take responsibility for their crimes. Harsh yes, and that judge is probably known for being harsh...but, if dude appeals to higher court, and his attorney gets the case heard in front of more sympathetic judge and jury...his time will be lowered or he will recieve a fine.
There is a saying in the American Judicial system, "Justice is blind, and she is a bitch."