(please forgive me if this if old news... I remember reading something about rogue mercs killing people in town, but i didn't understand how it worked. Apparently the game I was in never heard of this bug either.)
10 minutes ago I joined a dueling game with my level 16 druid. Shortly after I joined a level 76 Paladin joins and hostiles the entire game of low levels. He then runs outside into blood moor and then his Rogue merc starts shooting fire arrows, and regular arrows at me and the rest of players that were near the town entrance. We all died. After this happend he explained to us that his necromancer friend would cast his clay golem in front of one of us and the rogue merc would shoot the clay golem, but his friend would unsummon the clay golem before the arrow would hit it, so the player behind his clay golem would be damaged/killed even though he/she was in town.
http://www.imageshack.us/img1/8124/Screenshot007.jpg
Here's a picture of me, and this sorc dead inside of town because of the bug.
Notice all of the dead clay golems everywhere.
Linear Mode
