I don't know how much Richardson got his hand on the ball. Lopez was on Johnson and rode him the whole way. Richardson barely missed tapping the ball out on the rebound so Vandy didn't get a put back. McBee stood there and let his guy go by uncontested to the rim for the put back though and he even acknowledged it in the post game.
Go to 4:27 mark.
It's hard to see from that angle at full speed,but on the replay's of the live broadcast they showed another angle from the baseline in slow mo,and it is vary clear Richardson sticks his hand in there and pulls at the ball. Right at the time the vandy player is picking up his dribble to go up for the layup. Causing him to regroup for just a split second before going up with the shot. I agree after looking again Lopez being there helped, But i really think since Lopez was just standing with hands up. Had Richardson not got his hands on the ball the Vandy player goes over top of Lopez for a much easier shot.