McClain was saying for at least a week before the draft that the Texans liked Robinson better than Hall. What he wasn't saying was the Texans would end up with him only because Hall would already be gone. I've been listening to JM for years and this was one of those times when you could tell that he had some good info and he wasn't just blowing smoke. I'm guessing the MeAngelo factor came into play, which is the same reason the Texans would have taken AJ over Rogers last year if both were there at 3.
Hall and Robinson appear to the clear best of the CB bunch. Hall was rated by most pundits as something around a 8-10 pick. Robinson was rated around 10-14. Sure, Hall has better size and he can return punts, but factor in the intangibles and I could see where one could be ranked above the other on draft boards.