Testing Fan Clutch

On the show Wheeler Dealers, Ed China tested a fan clutch by grabbing it with a leather glove while the engine was idling (already warmed up, I recall). He could hold it still, which he said showed that it was bad. Perhaps if you lose a finger, you should jump for joy since that proves it is good? Some say that if good you will hear the wind blowing like a hurricane if it is hot, but I have never noticed that.