Bec:
I am so sorry to hear that this happened to your brother. It is good that he realized that this was a lesson for him, and that he will act differently in the future. Your dream was definitely a premonition of things to come. For anyone who has dreams of this type, we never know if we should act on them, and in what manner we should act on them. My personal feeling here is that if you had cancelled the party, your brother would have simply had this experience somewhere else. Bot you and his wife had premonitions, so this was something very important in his life. What do you take from this experience? That this same thing can happen to you, and that you need to act very carefully when it comes to drinking. I would also say that drinking is a symbol for something else in your life that you are working out internally, although I do not know what that is. My suggestion would be to take into dreamtime the question "What does this dream mean for me?", and see what messages your guides bring to you. I would also start a dream diary, where you write your deams down. Going back and looking at our dreams helps us to understand them better.
Blessings,
Bonnie