Well, how does the game know that I am going to become evil when it first begins? Unless the programmers implemented a psychic subroutine in there somewhere. That is, before I ever make any moral choices influencing my good/neutral/evil choices. The robots do not change during the game, the robot you have initially is the same one I always have for the rest of the game.
It only takes a few turns to research the first tech anyways from the start of a game. Terrans are neutral to start out. I always research a tech before colonizing my first planet (when the moral choices start popping up). The 'evil' looking Terran robot was showing up when I was neutral, as well as when I later was 'leaning evil' and when I 'became evil'.
I've also had the neutral looking robot appear in the beginning of the game for Terrans, which stayed there even when I have become evil.
EDIT: I did look at the bik files for the robot animations and see there are 6, 3 for terrans and 3 for all others.