Why doesn't poisoning count?

There was a Homeland plot point about hacking a pacemaker, which I believe was based on fears about Cheney's pacemaker (or continious flow device). What we recognise as a hit job is too overt and we've likely missed the covert reality.

Another way it might have passed us by if it was in a western country but not a western victim, eg Israel kills an Arab leader at a convention.