Hello, before I go on to explain how people do this I ask that nobody reading this attempts to do this... I am merely posting this here in hope the developers will provide a fix.
This is a bug involving the Baradin's Warden Battle Standard:
http://www.db.pandawow.me?item=63377
and it's horde equivalent:
http://www.db.pandawow.me?item=63376
(Note: Yes, I am aware these items are supposedly only usable in Tol Barad, this must not be the case however.)
If you have the rare chance to look prior to dying immediately then it is common for you to see (in cases that do not involve 3rd party software) a brown-esque banner that provides a buff that increases damage done by 10%, (I believe this buff is named simply 'Battle Standard.') I witnessed this banner in ALL three of the instances that I experienced instantaneous death, a monk killing people in Elwynn on this day this was posted (7/24/2014), a DK ret paladin 2v2 team, and a MW/WW (Double Monk, the same monk that was killing people in Elwynn)
This is something like what the combat log would read after one of these instances
http://imgur.com/6DcxcBI (Unfortunately I did not screenshot my combat log after said monk killed me.)
Please fix this immediately...
-Hartmanptr (PandaWoW Fun)