He has a speaking impediment/stutter. Sheesh. (not talking to you Mellow)
By the way, hear's an article with some really good info.
https://www.cbssports.com/nba/blog/eye-on-basketball/19304565/nba-draft-combine-dozen-winners-and-12-more-losers
Yeah, but all the TV guys talk about he is a lot better off camera, so there must be some kind of anxiety/nerves brought on by the camera.