Yes, Matthew Weiner is aware that Mad Men screwed up its Le Cirque reference
In addition to collapsing TV universes with its 30 Rock reference, last Sunday’s episode of Mad Men created a wrinkle in the space-time continuum when Christina Hendricks’ Joan said she’d made reservations at Le Cirque—a restaurant that would not open for another six years. When confronted by the paradox at a recent Paley Center event, Matthew Weiner commendably didn’t argue that he was intentionally making a statement about his characters’ increasing uncertainty about their place in the rapidly evolving era, or blame it on a wizard. Weiner did at first jokingly attributed it to an “ad-lib” on Hendricks’ part, but finally admitted, “No, it was a terrible error, and I think that the pleasure some people derive from this mistake makes it more entertainment for the show”—which is a very nice way of saying, “Whatever, nerds.” Weiner also confirmed that the 30 Rock nod was intentional, and presumably added that he hopes viewers will enjoy next week’s episode, where Pete finally lands the America Online account.