Let's agree that my use of the dubious term "Chinese wall" was inappropriate, and switch to another term like "ethical wall" or "confidentiality wall." Law firms use these devices to avoid the harsh consequences of imputed conflicts of interest.
I haven't found a lot of case law in Colorado dealing with this, but here's a link to
People ex rel Peters v. District Court, a case in which a firm was disqualified from serving as defense counsel for a murder suspect. The facts are different from BM's case, and the ruling doesn't control the outcome, but you can see the principles the court is trying to protect.
From what I see in this case and the few others I have seen, the Supreme Court seems more concerned about the principle of loyalty to the client (and related duties of confidentiality and independent judgment) than whether client information actually passes to a screened lawyer. I offer this case link for those who want to go deeper into this issue.
That's what I am concerned about in this case - the attorneys' duty of loyalty. BM's interests may well conflict with SD's before the end of this case.
He wants to keep her on side, and prevent her from telling investigators what she knows. But her best interests might well be served by making a deal to testify against him. How can a firm with a partner who is married to BM's attorney exercise independent judgment, and loyally advise SM concerning her options if the DA makes an offer? And how can the court be satisfied that SM's confidential information is not being shared with BM (and vice versa) in casual conversation within firms and then between Ward and his wife, Nielsen. Human nature being what it is, a confidentiality wall is not sufficient given the pressures involved in BM's case.
IMHO as a non-attorney, the senior attorneys at the McDermott firm should think very seriously of handing SM off to another firm before January 11.