I looked at the logs and did not see that many deaths to melee hits. I think that Sev and I have the taunt schedule worked out, so we may not have a problem anymore. We should taunt immediately on Fading Light.
I believe Sev can bubble or some other pally ability to get rid of the tetanus debuff. So the strategy I am thinking of is to kill the terror I am tanking first, and let Sev bubble and then, continue to tank or kill his second.