I experienced the licence fail again today, and it happened in a very remote place with no cell reception. (Which sucked a bunch) So I am glad to find this discussion which shined some light on the issue. It happens that I did allow my phone to do a firmware/software update early this morning. And thinking back to the last time I had licence fail, it had done that same thing on that day as well.
So I can confirm, this will not happen from a restart.
What I still wonder is how best to deal with the situation. My concern is that I listened to music from my phone for most of the day before it finally failed its check in the early evening. So how will I go about forcing a licence check straight after an update, before I drive off away from civilization?
If I can't listen to my favorite beats on a long drive, I might end up having to listen to the voices in my head for hours on end, and that can't end well. :/