Every brand has their own definition of "ambassador" and what their duties and responsibilities are ... but, with little argument, it's clear that the primary role of a brand ambassador is to reflect the brand.
Did Dean Potter reflect Patagonia's brand in a high-profile PR stunt on Utah's Delicate Arch? Perhaps he did.
Patagonia's taglines are "uncommon culture," "the soul of the sport," innovative design" and "enviro action."
Judging by Patagonia's passive PR response, it sounds like they agree that three out of four ain't bad.