Based on what RR said, this GM is not willing to tolerate something that is different than what he had planned on = Railroad.
And, conversely, the players is unwilling to work within the bounds that the GM set up.
I think we're at cross-purposes for good here. I see the GM setting a scene, giving the source, and effectively setting a stage for the kind of game he would like to run. The other players, except RR, understand what the setting is and agree, implicitly at least, to partake of that world as though they were participants in the world, choosing to portray "heroes" as set out by the basic literature. RR was unfamiliar with the source material and did nothing to educate himself on it before the game session.
When the game proved itself to not be what he thought it would be, rather than accept the social construct that he was observing, chose to rock the boat against the wishes of everyone else at the table. After the session ended, the GM took the RR aside and told him that his play style was not suitable to the game the GM intended to run.
You call that rail-roading. I call that setting the bounds for the game and establishing the social contract that the GM would like to set. RR is free to accept that contract, attempt to modify it, or reject it out of hand. If the GM is unwilling to accept changes to that contract, then RR is left with two options--fall under the contract and accept it despite his preferences, or reject it and sit out the game.
Frankly, as I said, were I the GM, I would find a way to allow RR's character into the game with the express understanding that he is playing a very specific type of character, and that his clashes IC with the other members of the group would be good fodder for the game. But I'm not the GM, and I can understand a GM who would rather not allow "evil" characters in a game where he wants everyone to be "good."
Since you think my analogies are out of whack, I will leave it at that.