I was just killed while accessing the ladder to climb down from the very top roof of the control tower on the airstrip. I know what you're thinking, and no, I was not moving at the time.
I simply scrolled with the mouse wheel to "Climb Down" while in the crouched position, which caused me to spring forward and over the ledge, after which I received a message that I was dead.
I've heard this is a common issue with accessing ladders.