He got to the freethrow line and then spun and the defender who is >1 foot shorter than him essentially tripped him (foul called) in a "pull the chair" move that's absurdly dangerous for a player of his size. Again, you can say what you want, but the League needs Wemby. Every team in the league charges much more when he comes to town; he's a cash cow and they need to decide whether much shorter guys tripping him/pulling the chair being the norm is worth the billions it's going to cost them when he spends his career injured or worse due to it.
Truth be told, the fans want Wemby in the paint. If the League's answer to this is, be a jumpshooter, well, that's also going to hurt revenue and the Spurs chances of building a dynasty on top of it (from Spurfan POV). Wemby as a jumpshooter is not a title winning version of him, or at least, not a dynastic version, in my opinion.