Truthfully they might be able to find a way to help him fall right, but one of the ways to protect himself to fall the right way way would require having both hands free to brace himself the right way, but with a football in hand, that's an issue.
He could be taught how to protect himself with a side fall which would allow his right arm and leg to take the force when someone comes from his left. Problem with that is again, if someone gets through on the right side, and Tua does not see him, there is little other then take the shot, try to stay upright, move the ball quickly to his right hand, and do a side fall to hi left (With left arm and leg taking the force).
As you can see here, this type of shot can no longer happen...
There is little that he can do unless he just fumbles the ball and uses both arms to brace himself. As well as the guided missile shot where the defender just smashes Tua (That has happened a few times already).
Miami should teach him how to fall, but more importantly that line needs to AT THE VERY LEAST, slow down the defensive player so at worse it's not a full out clean shot on Tua like this...
Though many might not believe it, Tua is a Tough kid, and can normally take it, but shots like those two are tough to walk away from. Put Tua more in motion against good pass-rushing teams, and what Marino1384 with the Bryan Cox Neck Brace might also be an option if things look bad with Tua taking too much punishment.