"There Were Chests?" Achievement Glitch.

[Disinfection]

So me and my friend were teaming up and she gave me a sword and we got good gear and stuff, then we made it to the deathmatch and I killed her, though I got no win particles or no win notification in the chat box. I've done this three times, I'm pretty sure it's a bug with the game and/or achievement.

IGN: Disinfecting

 

[Megaaa]

Maybe it is easier that you got picture or video evidence. than staff members can understand you better.