Clarification here
http://forums.lotro.com/showthread.php?t=86159
Orion has verified that it is a bug. Any member of the tribe caught doing this will recieve one warning from officers, who will explain that it is a known exploit and that the developers acknowledge it as such, and must immediately leave the raid they are in. Future incidences = kick from Tribe.
And So Sayeth the Violence

Scheduled to be fixed in 08/28 patch per Ramen:
http://forums.lotro.com/showthread.php?p=1057062