Re: Sensei -- drinking??
If the sensei is going through at divorce, and this has driven him to drink no one can help him. If he is coming to class drunk then he is driving drunk, he may be doing other things drunk like going to work etc. All of which shows great irresponsibility, and poor judgement, and poor decision making, in all areas of his life.
What is the dojo doing about this situation, are they enabling him? I would say to "lisa 1978" here's the opportunity, now seize the day, err the man. In this way, maybe some can talk sense into him to deal with his problems and stop drinking.
I don't think it is an Aikido issue at the core. It is a life issue and all is fair in love and war. And sometimes a man in turmoil just needs a sympathetic caring woman to comfort him.