First I wanted to say it must be the unbuffed regular plasma torps, but...

Apologies, Donatra aparently uses both Plasma and Photon torp spread. I clearly wasn't watching well enough up until now.

So, it can be plasma spread III that hit you. A couple torps each worth 20k kinetic damage and a lot of plasma fire afterwards. I'd say it's even worse than the photon spread. 3 or 4 plasma DoTs from Donatra at once will burn you alive.