I would think that part of the organizer's response is due to the use of 'inexcusable' in what looks like the initial contact. If a stranger contacted me and us

I would think that part of the organizer's response is due to the use of 'inexcusable' in what looks like the initial contact. If a stranger contacted me and used that word in reference to my actions, I would certainly immediately be on the defensive. This could have definitely led to the future lack of communication.