First point: it is a basic tenet of etiquette (like REALLY basic) that once you have said you will attend something, it is rude to back out because you decided you'd really rather do something else. There are acceptable reasons to back out of a commitment of this nature, but this situation is not one of them.
Second point: you obviously think that how the OP is behaving is incorrect. However, at this point, you've said it multiple times, at length. The OP obviously does not agree with your interpretation of events, and at this point, you really just sound like you're berating her, and trying to "prove" that she has been judgmental. None of us were there, so it seems to me that we all ought to be giving the OP at least some benefit of the doubt. It sounds to me like you are putting the worst spin you can imagine on what she has said, and if that's not your intent, you might want to think about how you're phrasing your opinions.
Finally, I think the OP would be best served, at this point, by cutting her losses and trying to forget about this woman and her husband. But that doesn't change the fact that the behavior exhibited is very confusing, hurtful, and occasionally rude. If the former friend and her husband don't want to be friends with the OP's social circle, they don't have to, but it sends an incredibly mixed message for them to play hot and cold. If they wanted to escape so badly, all they'd have to do is stop being available, stop answering emails, and stop going to group events. If they did that, people would assuredly stop trying to see or include them far more quickly than if the couple maintains sporadic and confusing contact.