Keep in mind that this island was connected to the Asian mainland and was part Of Sundland until 15,000 - 8,000 years ago. So...they weren't all that isolated until about 13,000 years ago.
Assoming a 95,000 year BP origin, These people would have hyad to survive the Toba explosion, and carried on in its cool aftermath (without fire?).
Whatever the scenario, that must be factored in. Agreed?