This happens on beta and blue: cancel magic / recant magic (and i assume all dispels) can be cast on anyone in guild. I believe it should be limited to only group members? People not in guild are not effected, but anyone in guild is treated as if they are in group.
http://www.eqclerics.org/forums/showthread.php?t=6107
IDK if there was a patch later that made it guild wide? I couldnt find anything on it.