The more I look at this, particularly the skull, the more it looks like a small whale, perhaps a beluga or blackfish. Only the report of hair makes me lean towards a large pinniped like an elephant seal or walrus. The dentition looks mammalian, too, although it is hard to tell from these photos. Incidentally, the photography, even though it's by amateurs, is refreshingly detailed and complete, and set up so it's actually useful to an investigator.

Previously unreported and unknown megafauna are extremely rare, but they cannot be ruled out. This is definitely worth following up. One good thing, no one can claim a "government coverup" if we never hear about this again. There is no conceivable reason to hide a find like this, and there is every incentive to publicize it if it's legit. And the skull is in such good shape a positive ID is assured. Even a graduate student in biology should have the quals required to make the ID if he has the skull in his hands. If we don't here more about this, it's because there is nothing there.