This is a valid tactic in FFXI, and my LS uses this to kill Tojil all the time (when we cant get a clean pull) Fail too see how you think it's an exploit. Many other dungeons have "keys" and barriers in place. This one doesnt. Seems intentional to me.

Also: My highest job is level 31 goldsmith. (30 pugilist) so I haven't even been to this dungeon. Just gonna put that in there since people think only people using this are defending it.