I think that these conspiracy theories are often a bit far-fetched, and that the simplest explanation is the most likely. The poor woman took all sorts of dodgy medication to calm herself down and wake herself up, not to mention a lot of alcohol. It's more than reasonable to deduce that her body was overwhelmed and gave out. It's the same with the Diana conspiracy idea. The fact is that the driver, Henri Paul, was not fit to drive, and crashed the car. Michael Jackson too died because of dangerous levels of medication in his system. It's all very sad but not particularly sinister.