The parents are both Black Pewters which is not a deadly combo. Sometimes things just don't go well.
Super blacks are not known to have this difficulty so I attribute this to something that went wrong during incubation. I think it is coincidence that both of them happened to be super blacks. One of them was on the bottom of a tall egg pile and may have been too moist (the vermiculite).
Most super blacks have a "duck billing" issue where their snouts look a little pinched.