The marksman in this particular case, as well as 4 other U.S. military operatives involved in the events of July 2 2012, were exonerated of all responsibility in exchange for their testimony against Lorance.
On August 1st Lorance was found guilty on 2 counts of murder by a 10 member jury comprised of military officers. During the sentencing hearing Lorance said I take full responsibility for the actions of my men on 2 July, 2012.
Sounds like he took one for his guys.
The immunity was offered prior to the trial, according to another account. So this was just stupid bravado.