Saw that you asked for some help over in Vertex's thread so here I am. So sorry for being MIA for so long. Crazy stuff has happened and it's tough keeping up with threads that are pretty fast moving these days.
First of all, I would put away the list for some other time. Now is not the time to bring it up for: 1) it would make W feel that you invaded her privacy from her perspective despite the fact that she left the list behind and 2) W is still actively engaged in a full-blown A with the OM with no sign of let up.
It would not be advisable to share or inform W that OMW has been around to chat with you. File it away. It is between you and OMW. I find it interesting that OMW confronted W about the A and to stay away from the OM. Apparently it had no effect on W whatsoever.
Yes, inaction is also action. Sometimes doing nothing produces the desired results.
I suggest that you pull back on the emails to W. Don't be too available to her.
What is the status of your situation right now? W living at home or? Where are you with S papers? How long has the A been doing on to date?
Crazy stuff has happened and it's tough keeping up with threads that are pretty fast moving these days. 