Stutter is a whole bunch of things! It's not just one single thing. If it was, we'd have consolidated that by now, I'm pretty sure. But we haven't, because there's still much to learn. Whether or not someone could stop stuttering after a car accident hardly seems relevant, I'd say. It asks us to imagine a particular version of what stuttering might amount to, and I just don't think that's a terribly useful way of thinking. There are things that work for some, and other things that work for others. That's where the work lies, if you ask me: Figuring out all the different ways we might improve the lives of people who stutter.