"Today, computer science and security experts from the University of Wollongong went public with their theory on what went wrong, similarly claiming the evidence of a DoS attack "does not stack up".
Professor Katina Michael and Professor Willy Susilo from the school of computing and IT argued it was more likely that the ABS had failed to appropriately dimension the resources needed for the site.
“Network activity maps on the night of 9 August don’t show evidence of an attack from overseas. All the maps are showing no activity for the night in question," Michael said.
“[The ABS] mentioned the possibility of four attacks, but by the time the fourth attack happened, the website would have been closed down to ensure the security of the data. This does not sound like a denial of service attack to me," Susilo said."
Citation: Allie Coyne, "Experts cast doubt on ABS' Census
DoS claims," ITNews.com.au, http://www.itnews.com.au/news/experts-cast-doubt-on-abs-census-dos-claims-433926