Mr. Maussen is the same guy that found some mummies in Peru, claimed they were alien and it was proven to be mummified children. I wouldn't get too excited by this. If 30% of retrieved DNA was unidentifiable, then 70% was. Not an expert but unidentified genomes are likely to be a result of divergent evolution and/or simply a result of a chemical breakdown over time.
I'd put my money on this guy having a real knack for finding dead kids.