For some reason, I'm quite enjoing this thread, even though it really shades into the playstyle wars type of discussion (edition wars are so 2008. We've moved on.)
First off - the words "Wrong", "Always" and "Never" being flung around need to come to a halt.
EVERYONE needs to understand that there are multiple ways the game can be played. One person's scripting is another person's railroad. One person's sandbox is another person's player pandering. Please remember this is help based on opinion. I agree that the OP had some issues and asked for opinions, but most folks saw a chance to educate, so try to help, not criticize, please.
WRONG! We're not talking about a hypothetical situation with hypothetical groups, we're talking about a specific situation with a specific player. If the player felt railroaded... HE WAS!
While, sure, the GM has a responsibility to himself to run a game that interests him (because lets face it, if the GM isn't having any fun, then likely nobody else really is either), he
REALLY has a responsibility to know his players enough not to put them in situations that they find totally unfun and frustrating. THAT, by definition, is a MAJOR GM FAILING.
All this talk about, "oh, that's not wrong, you just need a different group, or different approach, or whatever" is COMPLETELY IRRELEVANT. It doesn't matter what I think is appropriate. If this guy's player has a problem with the situation, he's got a problem. What does it matter what I think is appropriate? Or you? Or Elf Witch, or Li Shenron, or The Shaman, or anyone else who's chimed in to this thread? DMing isn't about the hypothetical, its about the specific. You can't say, "in theory, this is a great way to DM" if in actuality, it's completely unsuited to your players.
It's possible, of course, that the GM's style and the player's style just are going to clash and realistically they shouldn't be in the same game together. I think it's a bit much to say that we know that that's true so far. I think it rather more likely that this was a GM mistake in putting a situation out there that was extremely frustrating to a player, not taking any cues from the player that this was a mistake, and forcing it to continue anyway, and then giving the player a railroady ultimatum--either go along with my scenario or roll up a new character.
Pretty classic GM mistake, IMO.
All the theory about what other groups, or idealized, or hypothetical, or someone else's group would do, on the other hand--completely irrelevant. And all the advice that isn't geared towards being able to recognize cues from your players and react to them properly is BAD ADVICE, actually. In my opinion. Ideas like, "a lot of players aren't comfortable with talking about rape" or "a lot of players aren't comfortable with arrest scenarios" or whatever are really beside the point. That's speculation about the player, and putting in experiences that have no relevance to the situation at hand.
What's relevant is recognizing that the specific player wasn't biting on the hook that the GM was attempting to fish for him with, and in fact rather strongly objected to it. But the GM failed to pick up on this and charged forward like a bull in a china shop with the hook anyway, railroading the PC into accepting the hook, and then there was a major out of character breakdown between the GM and the player. Rather predictably, IMO.