The rafting and waterfall screencaps have still got me concerned, but I have come up with a hypothesis that solves both together. It involves flying from Calama (airport for San Pedro de Atacama) via Santiago to PUERTO MONTT, Chile. Just east of PUERTO MONTT airport is the Volcano Osorno and the waterfall that could be the one near there. 40 minutes in a very small plane from PUERTO MONTT is CHAITEN, which apparently cannot be reached overland, only by air and sea. Just south of CHAITEN is the RIO FUTALEUFU, which starts in Argentina, sneaks through a small gap in the Andes and ends up in the Pacific Ocean. It is one of the premier whitewater rafting rivers in Chile.
To quote: "Flowing through a colossal granite valley comparable to northern California's Yosemite, the aquamarine water of the Futa rages in a whitewater deluge, boasting some of the world's greatest rapids. Alfombra Magia, Mas o Menos, and Escala de Jacobo are just a few of the many spectacular rapids featured on the Futa." The season for Rio Futaleufu is listetd as December to March, which is consistent with AR11 visiting in late November when the volume might be a bit less fierce. For you Google Earth fans, put in for the Argentina/Chile border 43 degrees 30' 57.63" S and 72 degrees 40' 18.51" W . For the end of Rio Futafeulu, put in 43 degrees 38' 05.73" S and 72 degrees 54' 35.89" W. I had my eye at 14372 feet.
From there, teams would just hop the small plane back to PUERTO MONTT, which has lots of flights nonstop to PUNTA ARENAS.
Is there time for this? Only if it is treated as a prelude to PUNTA ARENAS and not a pit stop in itself. I do not see it as part of a double leg although that is a possibility.