All that was recovered was a couple fragments. The core apparently exited. I don't hold it against Nosler, it may have been a fluke, or maybe velocity was too high for the range he was at. I've never heard of a NP failing either.
What probably happened with that Nosler Partition is the front half shed its jacket, and the rear half blasted on through. Fairly typical of Nosler Partition performance, I have hunted with them for about 20 years. There is practically no way a Nosler Partition could shed its jacket.