Herzog’s statement is pure nonsense, as a full head would be analyzed on its own, he claims it took so long because there were so many mangled bodies, and her head was visible in the video that spawned the focus on her. Unless they found a cache of murdered people in Gaza that somehow hasn’t become a story of its own and then bashed her skull in to get a skull fragment rather than taking DNA samples from her head or body, there’s no way all his claims fit together. Her family’s account makes sense. She was killed with a shot to the head near the festival, leaving behind a skull fragment, then her body (with head minus fragment) was paraded through Gaza.
It might be a valid interview, just with someone who was lying for propaganda purposes.