You make a really valid point about how we may have been conditioned.
I think in earlier days I thought it was a very possible scenario that he was opportunistically taken, what with some of the history that belied some of the POIs in the past.
I would find it implausible that he was murdered by the FM, given away by the FM, that he fell and she hastily picked him up and hid his body.
I find if anything like that did happen implausible that the man she shares her life with would have no knowledge.
I find it implausible that in the time the FF left and returned for a video conference that this all happened- completely and utterly astonishing.
All my own opinion.