I don't want to tread on toes, here, but are you stating it is your belief that Jim must suffer for what he did to Murphy, in a story he created and that he controls, in a story that is not about her but about a different character (Harry Dresden)?
To answer the OP no I doubt it was the curse was used , but then again I and other readers don't know what Butcher has planned or if there is more behind the way Murph went out anything is possible at this point.
I get it that it's his story and he writes for himself and the people that want to read that adventure. All the other deaths of people that others where fans of (Susan, Shiro, Morgan) or where close to Harry where written and blended more into the book and story where this one sticks out like a sore thumb almost like it was written as a after thought and then jammed in late in writing process
It's the kinda ham-fisted way he went about killing Murphy on top of giving H and K shippers what they had waited for 16 books for only to then slap them in the face with BG and then in the interview where talking about why he did it and how he wanted his readers and Murph supporters to suffer the most while reading that on top then telling the people that are still around and pissed about it to keep reading is the thing that makes me want to ask Jim "Really you think that telling them to keep reading after you angered them and kinda slapped them in face is going get them to come back". I feel is a dumb thought on his part
And no I wish nothing bad or harm on Jim or anybody. Just that I have had friend's and family that have walked over this that would like to give Butcher a piece of their mind and I'm on the fence on fence about how I feel over it