FH101 lesson 1
Victoria BDM civil registrations are as informative as Scotlands. And like Scotlands, Victoria's death registrations on family history details simply are NOT first hand, afterall the person of interest is The Deceased.
So may I mention that EMW discusses the death certificate for Walter Wilson Elliot. There is NO such certificate.
There is, however, one for Walter WILSON, registered in the Australian state of Victoria in 1903. He was a widower, and likely the informant will be named on that official record. It won't be the mother of his children, she died several years prior. So the informant was likely one of his sons, giving answers to verbal questions posed by the funeral director, and jotted down in notes for later formally registering the death.. I do not see any issue with a grandson not knowing the maiden name of his grandmother.
There are also quite a number of obits, plus funeral and death notices freely available online via the National Library of Australia's TROVE website. The ship of arrival is named therein.
JM