Normally the certifications don't have the X rays, and even when it have its too small, so the certifications will make no diference, as the diference is in the evaluation of the X-ray and the attention to some small things.
I found something that can show a little bit of the problem in internet even if its really dificult to show, principaly when the majority dont work or are involved with veterinary medicine.
Like, for have A we must have perfect femoral head, congruent and the most equal possible in both sides...
Its a hungarian x ray of viszla with A results by the webpage of the UK club.
Here the x ray, its big
And an A dog used as exemple, its only for see one A the femoral head and about how it should look like, of course we have some differences dog by dog, breed by breed.
The femoral head format is something that must be also evaluate.
But its only a photo we cant judge well by it, but even looking here you already can see the diferences and see that something isn't well.