Why would a GM have anything to say about it, it's not like it's an exploit or something. A lot of people have been using the zariche to kill raid bosses. When you get the zariche, if you ever do, what would you do with it? Run around killing everyone you can in game or use it to make some in game funds? Also most of these people aren't truly soloing the RB, they just outdamage all the parties that are there and therefore get the drops.
I think the OP had it in his mind that soloing raid bosses with the Zariche should be considered an exploit of game mechanics and as we all know using a known exploit can be reason for a ban.