I'd guess the place works on similar mechanics as Tel'aran'rhiod. The first time Rand used it (although that was a fairly Power-incoherent passage of The Eye of the World) he made a staircase. Then against Asmodean, he was again running across steps, until he saw Asmodean just use a platform and decided to imitate him. Channelers have also demonstrated that they can change the appearance of their platform.

So I'd guess that people fall because they believe they'll fall. And once they're beyond any kind of landmark, it ceases to matter anyway. They might have changed the direction of their fall, or stopped falling at all, without a relative fixed point, it's impossible to discern.