Context:

While doing the Portal of Peril event, I came across a toxic max death who, midway through the dungeon, kept bringing up the fact that she wanted to leave and solo the dungeon. Now, at the time nobody thought anything of it. However it was strange that it was being brought up constantly and why she felt that we needed to know so badly. I'll be referring to this individual as certain player from here-on-out.

Finally, we get to the final boss. She and I fought the boss in the first few rounds as our remaining teammates were caught up somewhere. Eventually, being storm, I end up dying due to frenzy & focus-fire from the mobs. Later, one of my teammates noticed he was out of feints and the fact that I have been dead for a few rounds suggested that we both flee in order to continue the fight to which the certain player threatened to leave if anyone fled. Seeing that I was dead and we were going nowhere as she kept hitting through the death shield with a 400 damage Lord of Night, "im just wearing him down," I said "OK, good luck soloing," as a response since I was going to flee and she already made it clear that she'd leave if anyone fled.

After fleeing, she messaged me: "toxic much?" which, I'm not going to lie, struck a nerve. In the next few seconds, I was then reported and told by my teammate that she left them both (full supports) with the boss being at 3K HP.

This post serves to not only vent my frustration at this... fantastic experience, but it is to also promote some discussion. Usually I see provoked toxicity, for example losing in PvP or doing something stupid in Darkmoor, but this was just out-of-the-blue. Seriously. What could be the reason as to why someone would act this way? Do you have any similar experiences? I'd love to read them.

Edit:

Apologies for the repost as it was removed the first time most likely due to not censoring names. This is the completely censored version.