Last night on the NA siege server:
I put a siege ladder against the corner of a building and when trying to walk straight over the top of the ladder (ladder was angled so walking over the top corner of ladder) and drop onto a roof below, I got stuck in a falling loop where I appeared to be dropping through the roof of the building and then towards the ground. The loop ended after about 5 seconds and I was back on the roof.
On another map I put up a medium ladder against the corner of a building and this time tried to jump off the top of the ladder (again probably moving over top corner of ladder because it was angled) and got caught in a falling loop that sent me straight down from the edge of the ladder and this time to the ground because the ladder wasn't directly over the wall I was jumping toward. Jumping off the side, not near the top, of the same ladder worked fine but the top of ladders seem to have an issue.