I got an invite to join an in progress xp party in Aby LaTheine, I was going to finish leveling my PLD to 95 from 90. On my way there I teleported to the flux by the sheep and passed by a 95NIN soloing the T3 NM. The NM was at 20%ish and the player was at 50%HP, so I cast cure on him to get him to 100% and went on my way, trying to be a nice guy.
I no sooner got to the party, maybe 3 worm kills in, when I take a massive spike in damage. The NIN had died and due to my cures I was on the NM's hate list. Other people in the alliance came to help, but in the end I effectively MPK'd most of the party from doing a random act of kindness.