Liftback Issue Solved
Thanks to the posts here I was able to figure out my issue with the liftback opening by itself. My fob doesn't have left or right buttons, they are vertical. There is a button with a diamond on it. That is for the panic alarm. What I didn't know was that it is also for the lights "follow me" or whatever they call turning the lights on briefly, and if pressed for 1 second it opens the liftgate.
So - 1/2 second is lights, 1 second is liftback, 3 seconds is panic.
All this boils down to the fact that it is possible I set off the liftgate by pressing the diamond button inadvertantly for exactly 1 second!
Note to service advisor - the fob will open the liftgate.