Team USA docked 2 wins for cheating. Plus not sure it should be called team USA. Only 2-3 of the 24 sailers are American and boat designed and built by mostly New Zealanders.
What can I say, the Americans did it. They won the last 9 races to keep the trophy. This link explains how the hydro foils work to fly the boats. Quiet amazing.
Seriously though, congratulations to both teams. Despite bemoaning the demise (at this level) of old school Gentleman/Sportsman sailing competition, I have to admit this is a breathtaking accomplishment.