I fyou read the article closely you will see the phrase "Metal bits and electronic debris from the power cable hub". It is clear that the hub exploded not the computer.
Later in the article it mentions that the coax cables "were unsafely stretched over and near an electrical box and associated cables"
The probable explanation is that damaged insulation allowed the coax shield to come into contact with the POCO conductors or connections. The resulting gound fault caused the hub/modem to fail violently.
