I can understand why you would think that, the still you've posted they look pretty close to Fassbender with dark hair.
and the only thing that im not following you on this theory is because, even if Ridley would try to throw us off with this,
its that Walter is an android and even if he would give birth to a chestburster he wouldnt be in pain, he would just stand there and look down at his chest, followd by a sarcastic remark or simple one liner.