Me thinks you would have specify a lemon twist as lime is the traditional twist served with gin.
Also Jessica is correct about the twist, it's the rind of lemon or lime, twisted
in a fancy curly Q ( there is corresponding technique to this ).
Ms. J's customer obviously thought he was ordering lime as shown and seen served with Corona and other Mexican beers to somehow rectify a bacteria
in the water, which is of course rediculas but delicioso!