There was a point in the BDP-83 beta testing where I had a similar problem (BDP-83 to Onkyo 885 to Sony KDL-40W4100), but for at least the last five months I've been able to turn the TV off and continue to get audio from the BDP-83 via HDMI. It's quite possible that the issue is with the player itself, but identifying exactly where the problem lies can be very difficult. (Let's all say "thank you" to HDCP and give it the one-finger salute!) What your friend might try doing is experimenting with any other HDMI sources in his system - see if audio continues from a cable or satellite box or any other HDMI-equipped source when he turns off the TV.

Of course, you also have to watch out for CEC - I initially had CEC enabled at its highest level in my TV, and when I turned it off it would turn off my BDP-83 and 885.