Double Connection PvP Bug

1.  Open a Minecraft Server with PVP to false
2. Join the server with one player
3. Join the server with another player
4. With the first player, join the server from another client (The first client will be kicked)
5. Shoot the second player an arrow and watch him get hurt

 

EDIT: Forgot to say that the same happens with tridents.

 

Check the video if not explained good enough: https://www.youtube.com/watch?v=38hWHgtfc1s