For a Couple, Strauss-Kahn Is a Case for Silence

Re: For a Couple, Strauss-Kahn Is a Case for Silence, New York Times, June 20, 2011:A20.
I have one simple question: Why didn't the head of the law firm for which the husband works say to the client: I am sorry we cannot take your case, one of our partners is married to the lead prosecutor.
It seems to me that the couple should share recusals, otherwise defendants can play a game of choosing their law firm with the purpose of rendering highly competent and experienced prosecutors impotent.