Something to ask yourself is even with all the science in the world, will it even make a difference? If so, carry on, but it really sounds he has made up his mind. Who is everyone he has talked to and their frames of reference? Or why irons are better vs RDS's? If he's not willing to share that if asked respectfully, then he's made up his mind and things aren't going to change unless it comes from higher, or he has a revelation where he makes the discovery that RDS's are better than irons for reasons XYZ.