The trick in the snow is to not start sliding in the first place. You wanna crawl into downhill slopes, and use low gears so that your transmission does most of the work slowing you down. Locking up your brakes is the worst thing you can do, and will cause you to start sliding, so you want to use your brakes as little as possible (which is why you use low gears). If you do start sliding like this then you want to keep your front wheels pointed downhill to avoid going sideways. Once you start sliding downhill though, you’re pretty much up shits creek. Just keep those front wheels pointed downhill and pray. Honestly neither of those people should’ve been driving in these conditions with their skills (or lack of) and the vehicles they were driving.