NBA illegal screens LA v GS

[Kansas Ref]

Please check 8:25 mark, 4th qtr, La v. Phx where defender maintained his legal vertically defending the airborne shooter; unfortunately, it was his unorthodox landing (i.e., on 1 foot) that gave the ref the illusion of a foul.
Were I to have encountered this type of play in my NF games, I hasten to say that I'd have been similarly persuaded.