One of my female friends touched my arm in a way I can only describe as a "caress"

I doubt it means anything as it's the same friend who unequivocally told me she was not attracted to me when I asked her a different but related question. But I liked it a lot, and I haven't stopped thinking about it since it happened. I figured she did it just to be nice or something, even though I have a vague recollection of reading somewhere that in some context it means.... something. I just wish I hadn't failed miserably to touch her back or grab her hand like I tried to do while walking away (she touched me as I was just starting to walk away) because I'll remember that embarrassing moment forever now 😆 but it's a kind of affection I don't think I've received ever before (or don't remember it if I have). I doubt it'll ever happen again though. It never does.