Have to agree that the article is hard to comprehend, so this might not be a problem under whatever method is planned in NSW. But ...
How does the iVote system (ie software plus operations plus user interaction) prevent vote buying? Hard to sell yr vote at a polling booth*. But can be easier to sell yr vote (and its corollary, easier to buy votes in bulk) if voting is done in the privacy of one's home. Or one's workplace. Or some other sort of place. OK, I'll accept that it takes some organising on the part of the perpetrators. But it may be worth it to ensure that votes go the way some nefarious elements want them to go.
I understand that in USA, the process of voting in person at a dedicated place in a private booth is called the Australian vote. We call it the secret vote. No one knows how you voted**.
* Actually, not hard to sell yr vote. But hard for the purchaser to verify that the goods were delivered according to spec, if you know what I mean.
** I have heard that in UK, the ballot paper has a serial number so that votes can be traced back to the serially numbered book they were issued from. Don't know if that is true. But might be borne in mind by UK readers when commenting on this thread.