Search Results: staying friends with an ex

You can go through my previous questions if you want to get a better sense of the situation, but here's the SparkNotes version:

I was talking with this girl that I reconnected with after college, for about a year. Due to a general lack of communication, and what I can only assume is some mental illness issue (yes, she has confirmed to me that she suffers from at least 2 mental illnesses), this girl and I shared a hot-cold something-more-than-a-friendship, that she has recently cut-off when I called her out on the general disregard that she had shown me. THIS WHOLE SITUATION JUST SEEMED SO OUT OF CHARACTER FROM THE WOMAN I REMEMBER!

Her ex boyfriend, while not in the picture, had stayed in touch with her for a while after their break up. They tried to do the whole "just friends" thing, and I assume that she was basically treating him as the significant man in her life. Apparently my former friend was under the impression that they might reconnect as a couple, but then never did, and he has since moved on and is dating someone new.

In hindsight, she really treated me like an after thought. I sort of justified her behavior by telling myself that she wasn't spending as much time connecting with me because of the greater emotional requirement than talking to her platonic friends, but now that she has publicly humiliated me by telling my friends to get me to leave her along and made it clear that we were never in any kind of a relationship (despite what I believed to be some pretty firm flirting); I am curious to know if any of this was real, or if she straight up played me, or maybe even if her mental illness is causing some wacky nonsense. We are long distance, and she's saying that my messages were scaring her.

You have to understand that this was really sudden and got really ugly.

I want to reach out to her ex, to ask if this kind of behavior is/was typical from her, or if I'm an isolated incident, but I don't know if that would be appropriate. What do y'all think?