This is why I analyze the client's behavior as a risk metric before taking them on as a client. If they are 1) Ignorant in Finance 2) Stupid (Being kind in this case) 3) Emotional I have placed certain things in place to offset risk. It really sucks when you KNOW its fraud and they don't listen!!!!
I have learned over time that if they are willing to things like this it takes time away from you being productive, so I had my attorney draft up clauses in my contract to protect them from themselves.