When I do /endbattle as a spectator, it says "Player is not in battle" and drops me out of the battle screen.
The player that's battling then has a crashed battle, Run causes an error in console, doing a move will sit on waiting as well.
Doing /endbattle as this player will also say "Player is not in battle" but end the battle anyway, the wild pokemon won't start moving again until the battling pokemon is recalled.

This is the error thrown when the battling player clicks Run.
https://pastebin.com/jGcaRk4q

The command is being used as "/endbattle" to affect themselves.
The admin node also isn't given to said player.

/endbattle does not take spectating into account, so this is actually an error with the command itself

/endbattle took spectating into account but handled it incorrectly.