The Torres Strait is full of small islands bridging the 150km gap between PNG and Australia. Not only that, but much like the Strait of Dover or the Bering Sea it was most certainly a land bridge until the holocene, and it remains extremely shallow.
(If Wikipedia is right about the time of Tasmania's separation from the Australian mainland and Tasmania was already populated at the time, the feature would've had to have been preserved on both sides of the Bass Strait for about twice the time between modern English and Proto-Indo-European.)
It isn't possible to verify a claim like this (and therefore, it also isn't possible to honestly make a claim like this...) - there are plenty of traditions that claim to draw on 70,000 years of history, but no reason to believe that they actually do.
Some versions of the Sumerian king list document that a single king reigned for 36,000 years.