Directionality of Mac Pro Bluetooth

So I finally got round to testing my theory about the Bluetooth on the 2009 Mac Pro. I reorganised my desk so that the Mac Pro is behind my 24“ Mac Cinema screen with the right hand side (as seen from the front; the side with the panel) facing me. I’ve had no keyboard dropouts nor jerky mouse movement yet. The mouse was almost unusable with the Mac Pro in the same position but with the other side facing me. So it seems that the bluetooth signal can only penetrate out of one side of the case! That must have been a facepalm moment for the designers.