It's a good story, but I'd be sceptical about this one for two reasons : firstly - Samuel Smiths barrels and John Smiths barrels use different fittings to attach the barrels to the pipes for dispensing the beer ; would the manager really go to the trouble of changing the fittings on the end of the pipes for the sake of a couple of days before a delivery ? Secondly, did the manager think that his regulars wouldn't know the difference between keg John Smiths and SS keg OBB ? The biggest clue - keg OBB tastes of something, John Smiths doesn't !