Hi BigShow,
I too fly the Inspire 1 pro with both DJI Go and Litchi. My experience was very similar to yours with a few exceptions. I too was on a long flight, returning home (manually) after a LOW BATTERY warning, dropped down in altitude to 20 feet, coming in for a landing 10 feet away, but under a large oak tree. Almost to the ground and the Inspire did the same as yours, full speed vertical climb - right into the largest limb of the oak tree. I was stunned watching it crash right in front of me 10 feet up and no controls would stop it - no loss of GPS. After repair DJI said that it had reached the "Critically Low Battery" threshold and automatically initiated RTH!! Of course DJI says this is operator error, but since then you get an audible for both Low and critical thresholds. Do you remember any verbal warnings? Or did you have accidentally turned down the volume on your device?
Just sharing my experience....I now make sure the volumes are turned on full on all my devices...