What, short sighted people? It is quite plain there was an extra crewmember on the flightdeck, this person 'thought' there was only one left. NO pilot would exit at such a stage and waste time in the cabin! Instead of just a query, the original questioner made a dangerous assumption- there was only one pilot left. It is plain there was not- he could not see onto the flight-deck and see both pilots still sitting there. But he has been indulged as if he was correct, and that led to a new daft discussion.
He was mistaken. As simple as that. This was a trainer or checker relieving himself and his poor cramped legs for a few minutes. End of discussion (one hopes). It really was no more than that!
It would so help if people would just ASK a question instead of (as well) slipping in personal assumptions and accusations about the professionalism of the crew on the day!