When you get hit by tail rotor of hummingbird not tested with other heli, and you are not the last to get out of the hummingbird you will get same issue in video above.
i want to report too that on my side i'm not dead but for other players i'm dead and he can see me shooting and sometimes invisible or teleport major issue for pvp.
Looks like a synchronization mp issue.
https://www.youtube.com/watch?v=CsWGmBnxKKM