I just experienced the festering wound as well, healing @110 w/ a lot of HP Regen items, annoying. Didn't have a problem killing it, but I was actually after Lava Elementals (which are Not an elemental) on the next screen. Went there & got ganked, lagged, dead. No problem, I have 1 self res left. Dropped down a screen, took a look around, all safe, rezzed. Got on ethy, hit bandage macro - dead. Took a look around just to make sure I was still alone. Long walk back to town.
Yes, it can & will, last after death, it must wear off.