Bowen does that ALL THE TIME.
I've hated it for years, he does that and also steps under players shooting jumpers (who avoid coming down on his foot with theirs).
I honestly believe one of the reasons that Kobe has a hard time against Bowen is because of this move of putting his foot under him when he shoots...it throws him off to adjust for when he comes down.
Bowen is simply a dirty player who uses every trick in the book and then some to gain an edge, and since he plays with his legs and feet and torso, and NOT with his hands, he gets away with a TON.