For me, in order to call a foul on a player for undercutting an opponent, I need to see a player jumping mostly vertically and the other player moving into his opponent's space. This is not what happened here.
Red #32 jumped into White #42. White #42 ducked in an attempt to avoid being contacted. For me, Red #32 is responsible for any contact that may occur, but in this case I believe the contact was incidental. No foul.