Shawneegyrl, that defies logic and reason. So what’s new with chickens?
The feather-legged gene is supposed to be partially dominant. That means if you have two feather-legged genes in that gene pair you get the full effect, but if you only have one gene at that gene pair you still see feathered legs, even if they are not as full. So if you cannot see any feathers on the legs of either the hen or the rooster, the chick should be clean legged too. I trust you’ve really looked hard, otherwise you would not have posted.
You are dealing with living animals. That means strange things can happen. Most hens will stay fertile about two weeks after a mating. There have been cases where some stayed fertile for over three weeks. I’ve never heard of any going longer than four weeks, but maybe it is possible. Who would even bother to incubate the eggs?
There is something else working against that though. After a mating, the hen shakes to get the sperm into a special container near where the egg yolk starts its journey. A poultry reproduction specialist at the University of Arkansas was pretty adamant that the container operates on a last in – first out basis. The last rooster to mate with a hen has his sperm on top so his sperm will be the first out. Everything points to that Ameraucana rooster being the father, except the feathered legs.
So that leaves two possible conclusions. You have witnessed something really strange that by the general laws of chickens breeding should not have happened but did. Or that both that hen and that rooster are not the parents. There is another chicken involved somewhere.