And here we see a classic case of someone either inventing things off the top of their head, or adding two and two together and making five

the Warrah were indeed close kin to an extinct species found on the South American mainland -
Dusicyon avus - but diverged from said species around 16,000 years before the present, around 5,000 years before the first humans reached Patagonia and Tierra del Fuego, the closest regions of South America to the Falklands.
As such they were *
not* a domesticated form of
D. avus - which itself was neither a wolf nor a dog, and went extinct on the mainland around the 1700s, although there are scattered reports which suggest it may have survived in remote regions of Tierra del Fuego and Patagonia until the late 19th century.