He assured me that I was very mistaken, that Peru instead was famous for pisco.
He also assured me that I should quickly forget anything Chileans ever told me. You see, Chile and Peru haven't really hit it off since Chile grabbed up some Peruvian land after winning the War of the Pacific. In the 1880s, Chile fought Bolivia and Peru over the mineral-rich border territories. Chile walked away with a large portion of southern Peru, in addition to leaving Bolivia landlocked, as it remains today.
There is still quite the tension between the three countries. So you can see, then, why the origin of pisco is no small question.
But today I found official evidence that pisco is in fact from Peru. As it turns out, after the United States, Chile is the second largest importer of Peruvian pisco.
Touche, my peruano. Touche.