hi nsw bdm index shows when just use surname only in index search at http://www.bdm.nsw.gov.au/familyHistory/search.htm

You searched deaths for the last name Dotterill in the years 1798 to 1978
1 - 2 of 2 matches found but year don't match however maybe family beforhand came to australia

1768/1867 DOTTERILL ADA WALTER SELINA SYDNEY Buy Now
11/1869 DOTTERILL WALTER WALTER SELINA SYDNEY Buy Now
maybe they are related ??

where did you get confirmation he passed away in NSW ? tried also some variation nil result

then tried just Dot* as surname amazing cam eup with sam result as above

maybe went back to uk ? or otehr states of austrlia will keep looking
best wishes claire & family