However there are some ERVs that don't seem to fit this pattern. For example, the K family of ERVs (HERV-K provirus) is present in chimps and gorillas, but not in humans. Also, portions of ERVs known as CERV 2 and CERV 1 elements are present in chimpanzee, bonobo and gorilla (non-orthologous) but are absent in human, orangutan, old world monkeys, new world monkeys.
My understanding was that the HERV-K family of ERV's was present in humans (hence the name
humanERV-K). In fact they are still capable of being transcribed and are known to be involved in some cancers. Usually when this argument comes up it is referring to ptERV sequences, which as others have rightly pointed out, exist in non-homologous loci so are the result of retroviral infection after the human and chimp lineages split.