Sanctum: Massive unexplained DoTs still present (ref: 255,724,458)

Just died in a room on the third floor (trying to get my 3rd set of ascendancy points) in an extremely rapid way. Really makes me think of the "dots applied three times" thing, but different.

I was near one of the armour-breaking Urns, and stood in their puddle as I fought a snake. That was a calcualted risk, and I should have only take a little damage. However, I died less than a second from near-full ES. Watching the clip back I see my ES and mana were drained extremely quickly.

All I can see that might have caused it is that "Monsters remove 5% of your life, mana and ES on hit" was somehow applying to every single tick of the DoT from the Urn's puddle I was standing in. But DoTs like this should surely not behavre like a hit every server tick?

I had no other damage-related afflictions.

https://steamusercontent-a.akamaihd.net/ugc/26556371907312586/B62403E5094489C5D42F7411448A88BF67216289/
(valid for 2 days, but I can provide another if needed)