I think there is an element of truth that she felt I was being unresponsive.Ok so she has chosen, for now, to leave the door open.
I would avoid giving details on why you think things (like escalating emotionally), it is another form of sharing your feelings. Best to keep thing vague with a "I don't know, your quietness gave me the sense you needed space". The added bonus is that this will spin her hamster as she thinks about what exactly she did.
Ok so now you can wait to hear from her. Did your Good Morning text really come off as cold and shutting her down? Or do you think she was retreating to that position as she had nothing else to blame?
She obviously didn't like feeling that lack of control my short response made her feel and tried to have me chase. This did not work and she is upset.
The sadness she feels may be genuine but my interpretation when I remove emotion as best I can is that I played her at her own game. And she didn't like it.
Of course there is the potential for this being emotionally charged miscommunication. But that's my emotional side speaking.