I have a rather interesting story re: ofa - not to give you all something else to worry about.
I had 2 males x-rayed on the same day. The film was correctly labled with each dogs AKC number etc. In addition there were 2 seperate forms and 1 check.
The vet and I had a chuckle as the positions were so similar - you could actually lay one x-ray on top of the other and it looked like one. Didn't matter which way we did that - it just looked exactly the same.
After a LOOOOOOONG wait - got the results for 1 dog. I called and asked where is the other dog's info. They gave me a lecture about how x-rays are seen by different readers etc. So I waited some more - then they asked for the information about the 1st dog - and I waited some more - and called some more. Finally got the results back and both dogs - who had nothing different than each other - had different ratings. (they passed but to different levels)
Their explanation is that both dogs films were in one sleeve - so I asked if I could pay to have my films returned - they could not - so I to this day - don't know if they lost one x-ray and read the same x-ray twice or ???????
This was over 10 years ago - one would hope that their process is better now.