HELP Needed: Office is falling apart

No I don't mean that the building is falling apart. A friend of mine who works at a certain office told me that their office is falling apart because of the people around there. It was about a problem in the office that should have been discussed with all who work there. The person directly involved with the problem wasn't informed of the decision since he wasn't around (he was on a planned leave) when the decision was made. He felt that his co-workers intentionally did this when he was gone so that no one would say no to the thing they were suggesting. Now this office has been full of conflict and hopefully they don't fall apart completely. Is there anyway to resolve issues as such between co-workers? What do you think is the best solution for such conflicts?