Attorney Derrick Carlisle patronized the Riverside Caf and five members of its staff Monday. 'Excuse me, but I've always been under the impression that Manhattan Clam Chowder is red, not white,' Carlisle told server Diane Ptacek. 'And, when you get a second, please tell the bartender that a proper old-fashioned is made with a dash of bitters, not a whole ounce. Thanks so much.' 