There's a certain mission on Operation: Flashpoint, in which your entire squad sits innocently off the road. I happen to have a grenade. What would you do?
Moments later, my Sergeant drives up to the scene of the freshly smoking corpses that used to be his squad, with one slightly wounded, grenade-holding soldier left. I salute him, and gun him down before he has a chance to take me out. Unfortunately I do not get away with murdering my squad, as I soon meet the wrong end of an APC.
Another notable rampage was during the infamous mission to take Montignac. I was trying to see the other level that you play if your whole squad dies during the assault, but even when I ramped up the difficulty, increasing the chances of my squad getting killed rather than wounded, and even started firing grenades into them, I either got shot in retaliation or took the village successfully anyway.