Thanks for the feedback Pigskin. My mind is my enemy sometimes given the assumptions I make. After reflecting on everything, I realized that W was trying to be honest with me most likely out of her own free will, but I suspected that she had noticed my car when she drove off and had to 'fess up' as a result, but now I am thinking she may be telling me the truth that she had no idea I was there and could have not said anything to me.
After my reaction she mentioned that she shouldn't have told me (!)
It turns out W and I had been getting along pretty good the previous couple of days, and the fact that she was communicating with me about this when I didn't suspect anything was another step in the right direction even though I can't control OM's actions. I may have destroyed that progress now.
Most of the conflict afterwards yesterday, including an intense argument last night, was about whether or not she should continue to train with this guy. I told her that she can't go there since through no fault of her own the OM can choose to show up at the same time and she needs to limit his opportunities to run into her.
The problem with these kinds of arguments is even though I make perfect sense and what I am asking for is completely logical, she digs in and doesn't want to compromise (one of her 'endearing' traits I have dealt with). This is despite the fact that when the issue was first-discussed she said she 'obviously' couldn't train there anymore.
You are correct that my reaction didn't make me look good in her eyes, and likely drove her closer to OM. I have a strong suspicion she called him later to tell him how mad I got and to ask him to not come there anymore. This may seem like a victory, but any contact with him or OM knowing that he got to me is a setback I figure.
ME/XW:47 S21, D19, S15, S14 M:21 T:26 W moved 6/10 I filed 7/10 D final 4/12 remarried 8/12 W wants to R 12/10 and 4/11 but I decline