Sure, it’s impossible to get an ingrown hair unless you’re cutting the hair below the skin, but there are many other factors as well. As indicated most, if not all, of us cut our whiskers below the skin with no issues. How the hair is cut has more, I believe, to do with it. Cleanly (sharply) cut hairs like the one on the left will grow out normally. Hairs that get ripped by dull blades, multi blades, or electrics, like on the right, can snag as they grow out and end up being ingrown.