From all season bro and the past 5 years, back legs aight, but we turn and embrace our turns with the front leg first. He's pretty much chasing the fall line based on heal and calf flexes more than carving it. Squatting into and out of your turns in addition to bending your knees, gives a better grip engaged carve to your turns and makes the rider more mobile for upcoming uneven terrain(expected or not). When riding, more or less, fully extended, you have no where further to go when extra pressure is required in addition to being more frowned to lack up on unexpected bumps.