I'd love to give him that excuse, but I'm afraid that he was thin as a rake.
Regarding the student - I understand that she has no recollection of the accident but I believe that she was also very close personally to the instructor, so I doubt that she'll get over it quickly if at-all.
The whole thing really is incredibly distressing; I can only hope that the lessons are learned thoroughly enough that such a thing never happens again. I suspect however that these lessons are as much for those who don't drink but might be able to intervene, as for those who have this problem.
Not making excuses for anybody, there are/have been other alcoholics in aviation - I can think of at-least one I've worked with, and I'm sure that there are others. If we see this, do we do enough?
G