buggy will probably get the blame, I don't know if oda intends to raise Mihawk's bounty.
Even if he beats an admiral, his bounty is already for being the wss, so when he just makes that even more apparent, is there really a point in raising the bounty when the bounty already reinforces the portrayal of his capabilities?
And theres that whole thing of zoro having 3.6bil after beating mihawk.