Do you see the blue line on the drivers screen that should be behind the car in front of you? If scrolling to narrow the gap with the car in front of you it will only go so far.
That sucks. You didn’t say but I assume everyone was alright. Sounds like you did everything you could to prevent it. I didn’t know the video showed the wheels or braking. My only recommendation would be to put it in neutral when going down hill in those conditions. I did this in my Ram and do...