I have it wired both ways so I can watch the cable/TV without powering up the whole HT system. When I do power up everything then TV and HT speakers are both on at the same time, which is how I originally noticed the issue. The TV video and audio always seemed to be aligned so I started using it as the "standard" to measure the 970 delays. I don't actually watch anything with them both running.
It just struck me as I was typing that I can probably do the same thing for bluray using the HDMI audio which I run direct to the TV to compare against the 7.1 analog audio fed into the 970.