Sorry, the pharmacist isn't referring to you, I was referring to the murderer. I did read the article, and that's a pity. Some of the greatest truths (especially about interactions), one can gather from literature, and this person didn't even read basic police procedurals for guaranteed catches. What I wanted to bring out is that if you're going to murder someone in the UK, don't go with poisoning or a hunting accident as the crime laboratories at New Scotland Yard are fairly competent. They are always prosecuted as murder. Instead, hit them with a car (especially getting T-boned on the passenger side seems to be a real common way over there), gas leak the place after dosing her with benzos, sell her off to Polish or Russian very polite gentlemen who'll take care of the dirty work, or take a tour of rural Scotland where you can push someone off the heather and drown them in the bog, or simply just get a divorce...Option 3 isn't illegal and would have probably been the best course even if financially punitive. But if you do the other two, accidents happen and even with a guilty verdict, it's rarely going to be the UK equivalent of Murder 1 due to the way prosecutorial conduct works. There's actually quite a bit of criminal justice literature in the UK on the difficulty of prosecuting indirect killing, because their law has a different tradition of culpability in those cases (where in the US, you still get nailed for it because we believe in looser interpretations of cause and duty that we can creatively deal with the circumstances where a strict interpretation actually disallows creativity). Just makes policing so much harder.
