Why not just cut his own arm and check if it has robotic components? ;P
I am not sure which ending will be canon, but it sure won't be the Minutemen. For MQ, that faction is literally treated as a failsafe: little to no effort was given to their MQ quests and they don't even have the "I won with Minutemen" achievement unlike he other three. If they were to be canon, they would have a main questline as long and interesting as the BoS and the Institute+Railroad ones.
Being good guys doesn't really mean victory. Beth makes your Morrowind character be responsible for a catastrophe that almost obliterated an entire nation. That tells you how cruel they can be, your TES4 character loses his identity and becomes a Madgod while your TES2 character literally gets erased from history. The hints in Skyrim don't promise a happy fate for Dragonborn either. They have a thing for making the endings as bitter as possible (even FO3 ending is bitter when you look into what the EC BoS turned into).
It is certain that evil guys will not win (as we kind of have to save the world), but we lack them this time. Anything is possible, really.