There are distinct differences between skulls from apes and hominids. Presumably there are enough characteristics in this find to allow the scientists to distinguish its hominid "status". Otherwise this wouldn't be described in such glowing terms.
As the monkeys (extra-evolved) said in Kipling's "Jungle Book"--"All of us believe it, so it must be true." This must be the definitive missing link, or they wouldn't be so excited.
A neat little piece of circular reasoning there...which is why I always hesitate to put my trust in the latest vogue of the "non-accountable" sciences. Find me a nice control group, and I'll take you more seriously.
Non-accountable scientists include much of the theorists of the origins of life, matter and humanity. They find thigh bones and suddenly are telling me that the bone's owners can talk and build houses. They find some pollen with a corpse and claim elaborate funeral rituals, complete, I suppose, with an elegy in iambic pentameter. Who's to say they're wrong? Are they not plausible? And don't get me started on the Big Bang.
A pharmiceudical company developing a possibly dangerous, possibly miraculous, new drug won't write in fanciful language, but in tediously qualified exposition. An engineer responsible for a bridge which must safely carry millions won't engage in whimsical speculation...but these are the accountable scientists.