So sorry to hear about this, LS --- how awful ! What happened obviously IS possible, unfortunately. Rat poison is never wholesome stuff, as rats are, size for size, tougher than we are. And I think that chemical was involved in a highyl publicised murder case last year. Lenapain would be less reliably lethal, but depending on dosage. It contains a component that makes many of us very drowsy. But what is important isn't discussing the chemistry of this, but that you should see a good local counsellor to work on your grief over this loss