You mean this guy?

The My Lai Massacre (Vietnamese: thảm sát Mỹ Lai [tʰɐ̃ːm ʂɐ̌ːt mǐˀ lɐːj], [mǐˀlɐːj] ( listen); English pronunciation: /ˌmiːˈlaɪ/, also /ˌmiːˈleɪ, ˌmaɪˈlaɪ/)[1] was the Vietnam War mass murder of between 347 and 504 unarmed civilians in South Vietnam on March 16, 1968, by United States Army soldiers of "Charlie" Company of 1st Battalion, 20th Infantry Regiment, 11th Brigade of the Americal Division. Most of the victims were women, children (including babies), and elderly people. Many were raped, beaten, and tortured, and some of the bodies were later found to be mutilated.[2] While 26 US soldiers were initially charged with criminal offenses for their actions at Mỹ Lai, only Second Lieutenant William Calley, a platoon leader in Charlie Company, was convicted. Found guilty of killing 22 villagers, he was originally given a life sentence, but only served three and a half years under house arrest.

http://en.wikipedia.org/wiki/My_Lai_Massacre

Emphasis mine. Not sure you could have picked a worse example (unless you were trying to help me proof a point) but no there are many who commit these type of crimes in the military and never get anything. So yes I would say this was unusually harsh. I mean a whole 3 and half years under house arrest. Wow!