What your saying that was not a FA just a OBE maybe in the Real Time Zone. RTZ are made of your mind and the astral world so maybe you think of that or maybe that was really a real astral angel entity but that would be doubtful.
Well I don’t think it was a “warning” but it is possible that there may be things you can learn from your dream. To me, dream interpretation is a very personal thing and you will have to study the dream for yourself to see if you believe that it holds some special meaning for you. However, I do not think it is anything you need to be afraid of or anything like that.