[Spoilers] What I love about the ending
Just watched this movie again for the first time in a while. It just occurred to me how cool it is that we have no idea how Duncan passes Owen in the tunnel on the water slide. It's possible that Duncan found a way to actually pull it off, but even more likely that Owen assisted him in pulling it off. The possibility of Owen recognizing what Duncan is going through and finding a way to make him feel great in pulling off a legendary stunt in front of everyone just adds a cool level to their relationship.
And it all happens in the tunnel so we never know for sure. Perfect ending to a great movie.