Check out Sheffield United's goal against Manchester City.
The rules state that if there is another ball on the field the game is stopped. Furthermore, it also states that if there are any other objects on the field that can interfere with play, the game is stopped. In my opinion, there is no way this play should have gone on with all the balloons scattered in the box. It isn't Michael Ball's fault, it's the refs fault. The refs should have taken control of the situation on the field.