As others have pointed out I think it was a well drawn up play. It gave his team lots of options depending on what the defense did and left the decision as to what to be done with probably his smartest player on the court at the time.
Nice execution on Baby's part to set the screen when Ray didn't cut it close enough to Baby to make it work as effectively. I think the guys who set screens on this team take a lot of grief but that play is a perfect example of why these guys get caught moving on the screen so much. Either the man with the ball using the pick moves before the pick is set or the man for whom the screen is set doesn't properly utilize it and doesn't cut close enough to make the screen effective.
As for Doc I also want to give him credit for keeping his cool. I think 75% of NBA coaches my have picked up a late technical after Pierce was pulled to the ground by a rookie with 4 minutes left and no call was made. It resulted in a layup the other way and a 7 point edge for Philly. Given that Doc had been livid with the play calling and that the team was looking listless he could have gone nuts and maybe cost his team a point or two because of technicals. Instead he remained calm, gathered the troops, called a good play with Pierce going to the basket again giving the ref a chance at a make up call and got his team back in the game. I think this moment was better coaching than drawing up that last play.