I was completing the story mission “Estate of Decay”, towards the end of that mission the ceiling collapses and knocks down anyone not quick enough to dodge.
I found that if I timed my dodge and used it just as the rocks were hitting me I became permanently stuck in a knocked down position.
This was purely cosmetic of course, sort of like the bug with blink on mesmer or the aeroplane bug in beta. I was able to move and jump around the place all while looking like I’d been hit by half a ton of falling rubble (actually, this was kind of awesome).
Here’s a screenshot of my Charr jumping while “knocked down”.
