“…First, the person affected has the right to prior notice and an effective opportunity to make representations before a decision is made. Secondly, the person affected has the right to an unbiased tribunal. These two requirements are conceptually distinct. It is quite possible to have a decision from an unbiased tribunal which is unfair because the losing party was denied an effective opportunity of making representations. Conversely, it is possible for a tribunal to allow the losing party an effective opportunity to make representations, but be biased…”