No it is not. My ex was a professional hooker for a long time but she weren't no expert on human biology. She even gave a crap blow job.
Point is, you can be good at doing something without being good at talking about it. You can "know" how to do something as in being able to do it, without being able to explain how you do it, or knowing anything about anybody else who can do it.
Here's a brief post about this:
"But, it's not just that trying to describe your performance can disrupt it. Skilled performers often have trouble putting their actions into words in the first place. That's why those who perform at the highest levels should think twice about teaching their skills to others. When a scratch golfer in my lab, for instance, was asked to describe a putt he just took, he replied, "I don't know, I don't think while I putt." When your performance flows largely outside of your conscious awareness, your memories of what you've done are just not that good."
Being good at
something, and understanding what it means to be good at something
are two different competencies. Evidence of expertise in the former should not count as evidence of expertise in the latter.