Bogle and Chandler: New theories

In this excerpt from the ABC TV docu-drama Who Killed Dr Bogle and Mrs Chander? (2006), we learn that many theories attempting to explain the deaths of the couple have been tested throughout the years, but none have been proven. 

However, this clip also indicates that forensic investigators have hit upon a brand new theory about how Dr Bogle and Mrs Chandler may have met their tragic fate. 

The clip refers to a new 'witness' to the tragedy that can be presented for the first time: the river. Peter Butt's documentary goes on to suggest that the couple died from hydrogen sulphide poisoning emanating from the neaby Lane Cover River.