for approved airline crew to be carried on a cockpit jump seat.
That's not what makes this situation interesting.
First, according to the article he was not a FA. Whoever thinks that is just wrong. Nor was he a maintenance guy.
He was one of their electronic specialists who was deadheading on the flight.
There a big difference there.
If you have one of the companies electronics specialists on the flight. And he's standing on the FD. And he's telling you that they maintenance guys screwed up the repair.
That's an interesting
CRM issue, as I see it. It would not be the first time that someone deadheading on a flight has gone to the FD to be of assistance...and has in fact provided valuable assistance.