In addition to what everyone else has been saying, before beginning to do any work for them, I would also ask for as much of your anticipated fee for this to be paid up front. If this goes South, the doc will be looking to point the finger at you and developing a convenient memory of what was said and by whom, and use that as a basis for not paying you. In addition, as the sole fiduciary, he may well end up being personally liable for any shortfall resulting from a massive loss, in which case, you would need to get in line with everyone else who wants to get paid. If the doc does not agree, do not do the work, dismiss the client and sit back and watch the fireworks! You will be glad you followed these steps and possibly financially ahead of the game.