Ultimately, it's really the mob doing damage to itself via shifter trauma or headbutt and nothing specifically about your spinebreaker, artery, boneshatter, etc killing it like when poison or bleeding kill it off. Given that fact, it might just be too convoluted to track what caused it to properly reward PCs. (What happens if two different people maledict it? Who gets rewarded for causing trama?)

It's annoying, but overall a pretty small situation...hell, I'm just happy I can bleeding maledict stuff these days and get the exp, yet even when we didn't, we never avoided using the skills, since overall it was still faster. For now, I'd assume it's not going to be a simple fix.