If a kid is clueless about racquet control and spacial awareness, the pro should NEVER have been feeding balls towards the student. This is a common but horribly wrong way to establish tennis for kids or adults who don't yet understand the game to the point of recognizing the direction balls are moving.
Drop fed balls for kids is a must at this stage. Not only do they develop a desired swing quicker, (because they are not focused on trying to decipher where a ball is coming from and to), they learn to make much more solid contact. Not to mention it eliminates such calamities. (What would have happened to the kid had the ball hit them in the eye?)
I see pros and parents all the time try to teach tennis using the wrong progressions.
Dave Smith: Author, Tennis Mastery/Coaching Mastery;
Senior Editor, TennisOne; Dunlop Master Professional