Oneshotted as Hildryn through Shield gate during Arbitration

[Xyngrr]

During an arbitration, I engaged a group of infested at rifle range ( not melee ) being reinforced by an arbitration drone.
I had ~2500/4500 shield left ( not in overshields ), and my own active shield gate in addition to being bolstered by another Hildryns Haven. My haven was also running and linked to the group I was engaging ( had 235% range on ).
Popping the Arbitration drone chain reacted the group, and oneshotted me through both shieldgates with no enemies within melee or explosion range.
I'm honestly not sure what killed me, but whatever it was it bypassed both sheild gating instances/mechanics and dealt fatal damage beyond 15m from infested.
Theoretically a toxin or bleed could do that given I was not in overshields so I would normally look at a Toxic Ancient and their flat-out cheating assassinations, however it occurred exactly as my shot destroyed the arbitration drone with no toxic ancient visible, so the circumstances and timing indicate there's something else going on there.

I'm wondering if the damage push to linked targets on drone detonation included ME because my Haven was affecting it.

[GUARDOFLIF3]

>infeasted
>hildryn