Snow tires - 2 or 4

I think you just proved his point. The front went around the corner and the back didn't follow (although it will sooner or later). Now imagine if it was reversed, the front didn't go around the corner and the back keeps pushing straight ahead. You just hit that parked car. I always ran snows on all 4 corners, but regardless of whether I had snows on in winter or not, the best tires were always on the end that was most important to me, the front. The rear end will always follow the front, even if it takes a different route. I have plenty of miles on snow and ice, I will take front end control at the expense of rear end control any day of the week.