Yep, that is the correct way you should be coaching your players, make him throw the ball and dont send him to the line
You don't coach your players to not put your hands up at the 3 point line.
The shooting percentages he quoted are his overall shooting percentage, the majority of the time when someone has a hand up and contests the shot.
His shooting percentage will go up in situations where there is no hand up and the shot is uncontested.
When he participated in the uncontested 3-point contest, I believe his shooting percentage was around 70-80%. He got 20 points from shooting 25 balls (I don't know how many moneyballs he put in).