no matter if a pilot is flying off duty (jump-seating) or on duty (dead-heading)
OK, I guess we were divided by a common language.
I had taken your reference to jump-seating to mean just that - sitting on the jump seat, which our guy clearly wasn't doing, nor dead-heading on duty travel.
But any professional aviator, even when paying a full fare ticket, makes his presence known because he knows there might be an emergency and his services might be required.
Yes, it would be good to think that was the case.