That skull is nothing but a composite (they assert is 1.75 mya) 1.75 million years old, and is made up of a few hundred pieces that don't fit together all to well.
Just one place to start is that rear head area, another is the profile. But don't take my word for it, take the images they have as evidence, blow them up and start taking a look. Then put that in context to what they are suggesting. Then apply the most accurate dating method to the pieces, and notice the margin of error.
W.