Re: Releasing the TV before shutting down ?

Joerg,
 

Then there is nothing you can do about the pi, it's turned off.

 :-) There is a moment before its shut down and powered off that its still
running.  That would be a splendid moment to have the RPi tell the TV that
it should switch its inputs away from the RPi, don't you think ?
 

So you must check if there is a setting on your HDMI switch

 What switch ?  You mean the one thats part of the TV ?  That one doesn't
have a settings panel I'm afraid.
 Regards,
Rudy Wieser