Steve even reading in context I can not see how that impacts on limited atonment??Of couse there are false teachers and false prophets..so????????
The point is that the passage says the Master (Jesus) bought [greek = agorazo -- meaning literally 'to purchase in the market place', redeem] these false teachers / heretics resulting in their swift destruction [greek = apoleia -- destruction, utter ruin, hell].
This is not an easy passage to fit into a Limited atonement schema.