He's entitled to his opinion, but I'd hazard that the many lines of albino and the many generations of albino, all thriving in the care of keepers all over, mean that Albino BPs are not defective(except in coloration, which is a minor mutation).
I consider it more like a birth mark on someone. BPs do not need to bask, and therefor the albino doesn't affect them. I never noticed my albino keeping away from light, or hiding overmuch. Never heard of any issues related to albinos.
I think he's full of bunk, and just thinks anything odd is a "mutant" and therefor "defective". Let him have his opinion, he's entitled to it, however wrong it might be.