I used woodcock when training my lab at about 10mnths old and have never had any problems retreiving woodcock.
last week on our syndicaite a gun marked a woodcock down in a certain area and several dogs had been tried to retrieve it,eventually it was decided that it wasnt there and the gun had been mistaken, i was trying to pick a partridge at the time but went for a go at retreiving it after the bird was picked and my dog picked it relitively quickly,I'm not suggesting that my dog is a wonder dog(far from it) but wonder if the fact he had been retreiving them in training at such an early age