He doesn't seem different to me. Just tried again at level 40 (dps Guardian), with Kira. Got him down to a quarter of his health before dying a couple of times, but that was as good as it got.
He does an AOE - My trooper was holding aggro and I moved out of the blast area before it went off each time.
If your healer companion gets hit with this, they won't move - and it's likely to be the end for them (and for you, shortly afterwards!).