They're not the same. "Strong dry sherry flavor" could mean several things. You mean like a fino? Maybe some VA? Or do you mean like an oloroso, in which case that would suggest oxidation. That gives it a kind of metallic note and maybe some caramel. Hard to describe but unmistakable when you get it.
Cooked is different entirely. Cooked is cooked. It can taste like stewed fruit. Sourness has nothing to do with either.
I think the issue was just that it was a 2005 Pinot Gris from Alsace.