Yeah, sometimes they fall in.
I'm using Polyworks now and I've made a CTF map (everyone backflips in it
) which the Bravo team is trying to take something from a jail. Should actually be an INF map.
In this map, every "straight-up" jump is replaced with a backflip, and AFAIR there's only one "up-across" leap.
Oh, and I've attached that CTF map if you want it. And if you can't find that scenery, it's a ladder, and it doesn't really matter.