I've heard of it happening, but tonight in our make-up league match it finally happened to me. I was serving to the ad court and the serve return came back to me on my backhand side bouncing low at my feet. About all I could do was bring my racket down and give a little chip with an open face, (poor shot selection, I know). The result was a moderate height lob with tons of backspin. Since the downward trajectory was so close to the net, the opposition's net man wasn't sure if it would clear the net or not, so he let it bounce. After it bounced on his side of the net, it rose up about 10 feet and bounced a second time on our side of the net. He didn't hit it because he would have had to reach over the net to do so. Really weird! First time for me. He gave us the point, which I assume is the correct call.