Can you tell the a Sancere from a Pouilly Fume?

[Blue]

I have always thought I could...but, I was chatting with Roger Ormon, the famous wine Guru of Brookline, and he was telling me that in his 30 years experience tasting hundreds of both he could not tell the difference blind, and that in his honest opinion, no one not from one of the nearby villages really could...

Any thoughts?