I've long been a proponent of the "Caleb is (also) a robot" theory to explain Garland's genius "Ex Machina" (2014) [0]. This video [1] does a great job of fully setting out the thesis. Well worth a watch.
[1]: https://www.youtube.com/watch?v=YWS_AXKsemo
[0]: https://www.imdb.com/title/tt0470752/?ref_=fn_al_tt_1