The HPNA light is only on if a device is using that connection, usually a STB connected via coax (can be over twisted pair in rare situations like apartments). It sounds like your setup uses ethernet which would not turn on the HPNA light.
The previous scene is an excerpt from Brain on Fire: My Month of Madness, and just one of many hallucinations Susannah Cahalan experienced in 2009 during her month-long hospital stay, in which she was diagnosed with a rare neurological autoimmune disease, known as anti-NMDA receptor encephalitis.
2) Nomenclature. The nervous disease first reported in 1974, was named Viral Leukoencephalomyelitis of Goats (VLG). When it became apparent that arthritis could also result from the same virus infection, the name of the disease was changed to Caprine Arthritis Encephalitis Syndrome (CAE). It is now apparent that the virus also produces changes in the lung and udder. The name CAE however still remains in place.