Actually, an electrical fire would explain all of those things
I disagree strongly.
All pilots want to get on the ground as soon as possible if there is ANY fire aboard. Even ditching in the ocean is better than flying with a raging fire. Nobody in his right mind would be wondering endlessly in the airspace in a flight to nowhere for over an hour with a fire. Also somebody would be reporting this fire, MAYDAY, etc. if aircraft was flyable (say Swissair 111 scenario).