According to the article, this retrovirus is very similar to HIV. And all of us (gorillas, chimps and humans) have a protein called TRIM5α to fight against PtERV1.
Nearly at the end of the article the author says: currently, there is no explenation for why the endogenous retrovirus (PtERV1) has never entered the human genome.
Is that a typo? Isn't a missing endogenous retrovirus just basic heredity? Especially because humans have the TRIM5α protein against PtERV1 just like gorillas and chimps, which indicate that we used to have it, but we lost it due to how heredity works.
Or did the author meant something deeper that the average user would not understand without a lot of pre-knowledge about genetics?