Soccer is a sport that recognizes all its participants as having specific roles in the game. This includes players, substitutes, team officials and of course, referees.
These are the groups identified by the laws as being “official."
But there is also another group referred to as “Outside Agents.” This group has to be given a different technical and disciplinary treatment depending on whether they become involved in the game.
By Jose Borda, Revista Arbitros
What is an Outside Agent?
Tradition and common usage are very strong in soccer. Nowhere is this more true than in the definition of "outside agent." An "outside agent" (under any section of the Laws of the Game) is anything that enters the field without the permission of the referee and contacts or misdirects the ball or otherwise interferes with the game.
This means that outside agents can be dogs, coaches, spectators or like in this picture a balloon.
Interference by any outside agent will result in the referee declaring a stoppage of play, restarting with a dropped ball where the ball was when play was stopped, unless play was stopped inside the goal area, in wich case the referee drops the ball on the goal area line parallel to the goal line at the point nearest to where the ball was located when play was stopped*. But if the outside agent enters the field of play during the match without interfering with play, the referee will continue with play and must have it removed at the earliest possible opportunity. See Advice to Referees 3.3, 3.19, 10.7 and 14.7 for further guidance on dealing with outside interference.
If the interference is by a substitute who has entered the field of play without the permission of the referee, the restart is an indirect free kick where the ball was when play was stopped. The kick is taken after the substitute is cautioned and removed from the field of play.
Referees should note all deviations from Law 1 and Law 10 during the pregame inspection of the field include them specifically in their pregame conference and, where advisable, inform the teams as to how they will be handled in accordance with this guidance, and if appropriate shown the yellow card.
Procedure to follow
If a spectator or other outside agent enters the field when the ball is going into goal and tries to prevent a goal before the ball passé wholly over the goal line, a goal shall be allowed if the ball goes into goal. If the spectator or outside agent has made contact with the ball or has interfered with play, the referee should stop the game and restart it by dropping the ball at the spot where the contact or other interference took place.
A goal may not be allowed based on where the ball might have gone in the absence of such contact or interference. See “Advice to Referees on the Laws of the Game 14.7” (page 73) for a different approach to handling a burst ball and outside interference situations during the taking of a penalty kick.
If after a goal is scored and before the appropriate restart, the referee realizes that a foreign object was on the field at the time the goal was scored, the goal must be invalidated if the foreign object, or “outside agent” interfered with play, by contacting the ball for example.