Sierre is Cloud Guardian's brother, Cloud signed on from his brother's computer, and that's how the aid was canceled.
Also, Cloud didn't know Sierre had joined FORa until we started questioning him on it.
It isn't uncommon for Brothers/close friends to send aid to eachother, King Nai has sent me plenty of aid in the past.
I hope that Clears things up, if you have further question's go ahead and PM me here or in game.