I think she is just at ease now that she isn't with me and isn't afraid of things I will say to her.
Maybe friend-zoned is the correct term here...
We all have moments where we want to bash our head against the wall, me especially...had I done things differently I truly feel wouldn't be a single guy again. Oh well.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.