He hits with his arm only, then his other foot lands well after the ball is gone. He is off balance....he can not fly, so his foot does land. Weight transfer was not involved in the actually hitting of that ball, unlike most of his forehands.
At the start of the stroke is right foot is loaded - by the end of the stroke his right foot is no longer loaded and has changed position.
You don't have to be a physics major to understand that weight was transfered here. If he hit the ball and his right foot stayed loaded - only then could you say there was no weight transfer.