Of course they're fake. They literally say so on their site:
Thank you again for choosing to shop with us. In Australia, “UGG” refers to a general style of sheepskin boot rather than a single brand, which is why more than 70 registered trademarks across the country include the word “UGG” in various logos and designs. For this reason, we offer a broad range of UGG-style boots, including locally made options and styles produced overseas using Australian sheepskin, so you can select the pair that suits you best.
Which is all a load of nonsense. They're fake.