I am a ranger and i was fighting an infiltrator and some form of damage he was causing ended up doing positive resist. My resist are capped and there should be now way for someone to cause positive damage without some sort of resist debuff, but that fight was a 1v1 and no one was around.
Images of the combat log and my resistances.
https://imgur.com/a/BrZgtQ9
Images of the combat log and my resistances.
https://imgur.com/a/BrZgtQ9