CLYDE'S had been advertising fresh Dungeness crabs flown in from the West Coast during July and August, and with such a jet-fresh operation things can go awry. So they did for Virginia Hall of Washington, whophoned one day to ask if Clyde's of Georgetown had them. Assured that the Dungeness were in stock, she went to try them; the shipment hadn't arrived, so the manager invited her and her companion back for crab dinners on the house. When she took them up on the offer, the manager of the evening added free wine to the apology.

No wonder the hero of the Iran-Contra hearings has been Clyde's Old Ebbitt Grill.

HAPPY HOURS AND HOURS --

The hours are getting happier and happier these days, as hotels and restaurants compete for the after-work drink trade. Cafe Beaux Arts has extended its happy hours to 8 on weekdays, but while it promised such free nibbles as imported cheeses and mussels, I found nothing but standard mini-quiches. The Sheraton Grand ends its happy hour at 7; during this two-hour weekday event a different drink each day is half-price, and appropriate free hors d'oeuvres accompany it. Monday is beer with hotdogs, corn dogs and peanuts. Tuesday is manhattans and martinis with New York subs and soft pretzels. Wednesday's special is Mexican: margaritas, tacos and nachos. Thursday's upscale snacking is pa~te', cheese and crudite's, with non-alcoholic frozen drinks at half-price; and Friday has Polynesian style drinks with egg rolls, spareribs, wontons and dim sum.

THE LIST OF LISTS --

In the seven years The Wine Spectator has been pinpointing the restaurants with the best wine lists, Washington has been represented by only two winners: Jean-Louis and Le Pavillon. Now Aux Beaux Champs has been added among the 10 new winners from the U.S. and Europe. Chef Doug McNeill has, since 1980, built the wine list to the extent that wine sales are now more than $1.6 million, he told the Spectator. McNeill's list is a patriotic one, with California wines listed before French, starting with two dozen American sparkling wines. The list goes on to include, for example, a hundred cabernets; in all, says the Spectator, the length and breadth of the list is impressive, though no more astonishing than the prices. Those high prices are balanced, though, by the bargains listed as odd bins; this is a bonus of McNeill's computer system, which keeps the list up to the moment.

MORE HEROES --

At New Orleans Emporium, reported a diner, the waiter warned her father that a dish was very hot but he ordered it anyway. Then he found that indeed it was so hot that he didn't like it. The waiter took it back without a question and returned shortly with a milder dish in exchange. That is really going beyond fair to charitable.

And at the Occidental, a diner was charged only half of the wine's proper price. The diner pointed out the error to the manager, and was told that since the restaurant had made the error the billwould stand. Again, going to outstanding lengths to satisfy a customer.