Errors in genealogy are very common. Much of the research depends on the memory of the oldest members of a family. I’m no McCain fan, but this is a little silly.
I have been into genealogy since about 1998 and if I could have a nickel for every mistake I have found, I would be wealthy. There are records out there that someone with a very good imagination put together. It is very easy to spot them if you do a little more research. Someone can start with someone famous and try to find some kind of link to their ancestors. It does not have to be real. The same thing is true of people trying to become members of the DAR. That is why they started requiring proof which I do not want to take the time to do. I know it and that is enough.
>>Errors in genealogy are very common.<<
You can go to the souvenir shop in Edinburgh castle, for example, and they will match your family name to families that have pretty tartans on the flimsiest evidence, e. g. somebody with your last name used to live near the other family. Then you can buy your pretty tartan tie and wear it proudly.