The first thing that tipped me off was the scene in Interstellar where Cooper and Mann were wrestling and Cooper said there’s a 50-50 chance that your visor will break first, and Mann (without any hesitation) says something along the lines of “I haven’t had such good odds in years” proceeds to headbutt Cooper cracking Cooper’s visor. Is this evidence that Mann was in fact a robot? Surely no human would be able to process the implications of a 50-50 life or death game of chance so quickly.
The other quirk I noticed (but need to re-watch it to confirm) was when Mann started acting strange and robotic when he/it was saying something along the lines of "I'm sorry, I'm sorry, I'm sorry" in a robotic voice as it is slowly died.
I recall one of the characters mentioned: “the only thing that could never be programmed was the experience of death”. Accordingly, the robot exposed it’s non-human behavior when it tried to display the experience of death to Cooper.
After reading the lost chapter "Absolute Zero" I am even more sure that what actually happened was that Mann was merged with KIPP against his better judgment when he used the "Bermondsey" command to supposedly leave him on the planet "alone" i.e. KIPP and Mann merged therefore creating one transhuman entity with questionable morals i.e. sense of good and evil.
If you look carefully at the events that occur on pg 4 of Absolute Zero, you can see the moment Mann becomes suspicious that KIPP is hiding something from him. Following this, KIPP disobeys Mann, which as a human would be a serious cause for concern, so Mann trusts his instincts and immediately destroys the data that KIPP suspiciously claims is not useful.
Maybe KIPP was trying to protect Mann from losing "hope" that he would somehow, against the odds, find the information he was looking for (and therefore not going gently into that good night). With Mann's hope (data) destroyed (coincidental play on words of "Man's hope", our most human emotion?) KIPP was able to coerce Mann into using the Bermondsey command which I believe actions the transhumanist singularity. The final page of the chapter subtly depicts Man being merged with Machine, and concludes with the most profound of moral questions of what is good and evil?
Following the merging of KIPP and Mann, the transhuman entity was then able to secure it's own survival by constructing an elaborate plan to boobytrap the rescue team when it arrived, and steal the spaceship to return home, however this plan ultimately failed.
So far it seems like I am the only one on the internet to call this out. This is concerning because what happens when the singularity comes and we fail to recognize the subtle differences between humans and robots acting like humans?