IDK if there's already a word that can be used to describe the event/person when someone does something bad to you or anyone else first time, out-of-blue and without provocation and then you had to avenge and/or reciprocate in same/similar manner to truly and rightfully defend yourself.
Like "draw first blood" as in "Girl, I was just trying to make my point but you drew first blood by screaming at me out of nowhere".
But "draw first blood" seems very combat specific and military oriented, is there any similar term/phrase that can be used in friendly/casual/professional environment and situation where just General Public is involved ?