I understand the argument. The problem with this is just that it requires people who sacrifice their critical thinking abilities to an ideology in order to end up with a mass of people who stand so close to each other that they are best described by the equations of fluid dynamics.
The people in the center of the crowd who die had plenty of opportunities to get out, but they didn't; they committed to their respective ideology.
Sure, if you find yourself in a mass of people that is so dense that you loose any sense of agency, it might help to remember that you're just a molecule in the mass and go with the flow. But if you find yourself in such a situation, it's usually a clear sign that you haven't always been reasonable on the way there.