I shootet down today by an other caracter in front of a PVP. I use the new UI, i see the the animation of going down. In my excitement, i press "c" to stand up, and it works! My screen was black, but i can see him and i shoot him down and bandage me. After ~5 minutes, i wake up from my unconscious state and get a gree screen. When i was unconscius, i cant get in my inventory, but i can run away, jump and crouch.

This happens in North West Airfield behind the 8 hangers and the barraks on the open field. I dont try it again, but i think i can do it again if i try it.