I would be a bit miffed if I had no reflection. Having only half a shadow is bad enough.

I found out about RT and reflections when some hide/show clothing parts for Rhiannon's Elsa Wylde produced AO artifacts. I set up two mirrors at an angle to show the artifacts from all sides in a forum thread picture. Then somebody suggested making the clothes invisible to raytracing.

Sure enough, my next render came out with one clothed Elsa and three nudes. I put the pic in my gallery (Mirror mirror on the.... eeeeek!).

Well, that's my story, and I'm sticking to it.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)