It looks like the intruder may have been a loader from an earlier stop in Bangalore.
Some years ago a UPS 747 had the ladder hatch pop open over the Nopac and a loader from ANC came up. He rode to TPE, had no documents, so he stayed on the plane for the trip back to Alaska. He was fired after he got home.
A FedEx loader fell asleep in a 727 a while back and took a domestic trip in one of the aircraft bellies. FedEx dispatched one of their bizjets to retrieve him.