Peru, After doing the roll-the-gold-balls bit, you're 'taking the high road" back to Rutland's men.
If you stop on the second-to-last pillar (not the one you slide down), and try to traget the guys below, your crosshairs will be grey. Lob a grenade down, they'll both die. Thing is, if you do it early enough, the conversation you can hear will continue, even though they're dead. I found it amusing.