So bitch owners want to have "clear by parentage" studs TESTED because they DON'T TRUST the TESTS. Huh? Assuming, certificates are available, what exactly am I missing?

The sire may not be the sire. It's happened all too often. That's the reason Optigen won't issue certificates for "Clear By Parentage". When the AKC Gazette used to be published, every month there were dogs who's AKC paperwork was voided because a spot DNA test showed the sire listed was not the actual sire. As the song goes "your daddy ain't your daddy but your daddy don't know". I remember a couple years ago a breeder's boy, who was supposed to be dominant black was used and a chocolate puppy resulted. She announced on her website that her boy, much to her surprise, carried chocolate. She went on to test him for color and it came back that he was dominant black. They did DNA on the chocolate puppy and it had a different sire. If it weren't for the color, everyone would have gone on to think the first boy was the sire when he wasn't.

Huh? again. Just how would having the presumed stud Optigen tested instead of clear by parentage have made any difference in the situation?

If a dog is "clear by parentage", it means that both his parents have tested "clear". If,the male that you think is his sire, is not his sire, then there may not be "clear by parentage". Example, you have a girl(Optigen clear) in season and you breed to Dog A who is Optigen Clear. Unknown to you, your spouse or children accidently let the girl out in the yard with one of your boys who is an Optigen Carrier. They notice later and don't know that the Carrier boy has bred her. You breed her to the Clear dog not knowing she was accidently out in the yard with the other dog. Puppies are born and since you "bred two Optigen Clear" dogs (not knowing about the accident), you assume you have puppies who are "Clear By Parentage".

If the dog you think is the sire of your puppy is not the sire after all, it doesn't make a heck of a lot of difference if he is Optigen tested or clear by parentage. That is probably just as unlikely as the sire's sire's sire being wrong. The odds of either happening are really small. As in do not cross the street! You could be hit by a truck. Better to spend your energy making sure as possible the people you deal with are trustworthy.

I've heard of it happening with 2 different people and it wasn't a matter of them being untrustworthy. Sometimes oops breedings happen when you have multiple dogs.