In whigh case it comes back to the previous poster who says 'you have given cause x and y for this death, is that 90%, 75%? is it possible to definitively rule out causes a and b?' Particularly where cause b is foul play and the dead person was living with a man with a history of domestic violence that was discoverable (clearly, since it was discovered).
And even if none of that happened at the time, would the first investigation not tend to go back to the pathologist? Especially as the man's history was I think known by then? And if it wouldn't usually do this, what DID the investigation involve? And what did the SECOND investigation involve? And the THIRD? And if an investigation doesn't involve doing any of thevery things, why not and what are they for?
Nobody is asking for perfection, I get things wrong all the time like many professional people (some a lot less than I do). Buthe there are systems to challenge and check my decisions, and the most useful challenge of all is another person looking at my notes and saying 'but I don't understand, what do you mean, and how sure are you?'