Well said, anvilhead.
It has been my experience that the disease of addiction is cunning and no matter how deep into it a person is, they still seem to understand that they can say the craziest things and still be right (not mention the ones that love them will believe it). It is the nature of the beast.
HurtBad, for now, the best thing you can do is to set boundaries and consequences that are healthy for you! Your son, will have to come to his own realizations about his disease, but until then you need to stick to "just the facts". . .you know that everyword spoken from your son's mouth is a lie. . .ask yourself "what can be done that will allow me to make healthy choices for myself?" It has been my experience that no matter how I want to lash out at the people who seemed to be enabling him unbeknowing to them (the docs, his employer, etc.) that recovery for my addict will not come as a result to my desires to shout from the highest point that he is getting over on all of them!
So, before writing that letter think. . .WHAT GOOD WILL COME OF IT?