I'd have to assume they ruled his glove was above the fence. Perhaps, but that doesn't matter when the Indian's outfielder made contact with the fan's glove before the ball got to that point. The fan kept the outfielder's glove from getting to the height where he had a play on the ball. The fan's glove was clearly in play at some point, but I'm not 100% certain that the glove-glove contact happened while the fan glove was in play. Again, I think it was fan interference, but I could see how it could be viewed otherwise.