to protect his ankles which had to be surgically repaired after a ton of sprains earlier in his career. People think he's flopping, but it's just something he does when he senses a defender sliding under him. It's just not uncommon for that landing space to be encroached by a contesting defender. The NBA is trying to address it somewhat by categorizing that action as a foul, even if no contact, but that's a relatively new rule/interpretation and it's not consistently applied yet (although not a lot is consistently applied by NBA refs).