MARBLEHEAD-Selectmen are maintaining their vigilance where local bars are concerned n but this time they let the establishment off with a warning.Board members have voted to issue a written warning to Sweeney?s Retreat, 18 Atlantic Ave., in regards to an incident at the restaurant and bar shortly after midnight Saturday, Oct. 6.A local woman was charged with driving under the influence of alcohol after the car she was driving hit another car in the parking lot. Owner Phil Sweeney told selectmen he saw the woman at the bar at 9 p.m. and she was “very loquacious.”He said the accident occurred during an argument with her boyfriend over whether she should drive home.He told selectmen he was satisfied that his staff did not over-serve the woman, that she had “a couple of glasses of wine over two-three hours.”Selectman William Woodfin said Sweeney had never been before the board for a license violation before.However, Woodfin made the motion to issue a letter of warning, which will remain in the establishment?s file. If any subsequent violation should occur Sweeney?s Retreat could have its license suspended.?This is the course we?ve taken recently,” Selectman Judy Jacobi said, an apparent reference to the board?s actions on a series of over-serving complaints at Maddie?s Sail Loft this year. The vote on the motion was unanimous.