Oy...
The simple answer is that, up until recently, the
likelihood was that he was probably a human, but with slight room for potentially being a robot (some guy who supposedly invented a certain model of robot suddenly gets put in charge of a biological weapons retrieval team and told of the company's biggest secret? Really?
). Ever since the last film, the
likelihood is now that he was an advanced model of robot.
No, Call didn't bleed red, but it's hardly going to be the most difficult thing in the world and white fluid might have just been a legal necessity in 'civilian' models to differentiate them from genuine humans in a medical accident and so on.
There was always a slight possibility of the character being robotic. It's just much more likely now. Interpretations of scenes will always change if a different artistic director wants to go and revisit them. That's what's happened and that's simply how it now is.
