I don't see it at all unusual for the coroner to rule the death natural. Mr. Breitbart was under a doctor's care for heart problems. It is SOP for the death of someone under a doctor's care to be natural. The doctor signing the death certificate has a lot of do with the decision. I'm guessing the doctor who signed the certificate in this case is Mr Breitbart's doctor. If he is satisfied that the death is natural it is hard for the coroner to disagree. Does anyone know who signed the death certificate? Has the death certificate been made public?

However, the possibility of murder should be considered whenever there is a death of a controversial public figure. This does not mean concocting a conspiracy theory. It only takes a single person to perform a murder.