[Wright's whole Satoshi cosplay seems to have resulted from this fraud because when the ATO did catch him they asked the obvious question: "Where did the money you were supposedly spending come from in the first place?" Bitcoin was just hitting the news bigtime then so he claimed to be an early bitcoin miner, but the amounts in question were so large that he needed to eventually extend it to being Satoshi to try to make it make sense.]
[1] in AU instead of not charging resellers sales tax businesses just apply to have their sales tax paid refunded, and it more or less works on the honor system. So you can spin up a bunch of on-paper businesses, make some sham sales between them-- the buying side claims the GST refund, the selling side just goes out of business without ever paying the sales tax.
Imagine one rogue employee out of 10 commits fraud, do you get all your money back? No you get the billable hours + damages for the fraud.
If it worked the other way contracts would be longer than the actual work to be performed.