Cocktails at Ritz
Your friend was no doubt thinking of Chris McMillan at the Library Lounge. He's well known as a great bartender and historian of drinks.
Chris left the Library Lounge, unfortunately, a few weeks ago. Last I heard, he still has landed anywhere yet. So, no reason to stop here.
If you want good cocktails try Lu at the Swizzle Stick or Chris Hannah at Arnaud's French 75.