"Some time later another member of staff said: 'ooh, someone is drinking a very impressive wine, and at the bar!' That's when we realised".
The restaurant tweeted a photo of the two wines side by side, adding in capital letters: "They look pretty similar OK?!" The mix-up was seen as an effective marketing stunt for the restaurant as people are getting to know about it and they hope the same can happen to them, HuffPost UK reported.
Mr Becket revealed that the lucky customer liked the wine so much they asked for another bottle at the end.
But the venue has done any swearing in private and come out all smiles, writing on their Twitter account "To the customer who accidentally got given a bottle of Le Pin, we hope you enjoyed your evening".
The restaurant told the employee "one-off mistakes happen" and added "we love you anyway".
In a phone interview with The Washington Post, Beckett said the manager was from another Hawksmoor location and was helping the waitress on a busy night, and erred when picking up the bottle and handing it to the server.
A spokesperson said to i: "It was a very busy night at the restaurant and a very simple mistake".
Not wanting to cause a fuss the staff member "gently steered the customers toward another bottle of wine and kept quiet", he said.
It comes from Bordeaux's Pomerol appellation in the Catusseau hamlet of Gironde and only 500 cases of the 2001 vintage were made - hence the high price.
A "mortified" staff member who made the error has been urged to keep their "chin up" as "one-off mistakes happen".
"Its deep ruby/plum/purple color is accompanied by an extraordinary perfume of creme de cassis, cherry liqueur, plums, licorice, caramel, and sweet toast", Parker is quoted as saying.