Maybe it was coin buy-backs or something related to the GST "gold scam" the happened a few years ago? I believe several legitimate business got caught up in it. But that wouldn't be much money I presume? Likely they weren't charging GST on coins they should have (according the vague ATO rules) They probably appealed it for a while and ultimately lost, and they didn't have the cash to pay up, so was easier and less stress to simply shut down the company and declare bankruptcy. Guess who the 1st priority creditor will be....
In all the cases I know of, the only appeals that were heard were by another department inside the ATO. In each of these cases the ATO internal review admitted that 75% of what they were saying was incorrect, and reduced their assessment by 75%. Imagine if an independent third party had the opportunity to review it, and apply a rational industry wide policy.
To me that means they are 75% WRONG.
However, the 75% reduction seems merely a bargaining tactic on behalf of the ATO and not a genuine look at the circumstances in that business, or any serious consideration around interpretation of the legislation.
The bullying tactics used by the ATO (including garnishee notices as seen on 4 Corners - Google Richard Boyle ATO) are such that small businesses cannot fund any kind of defence, especially when the ATO will delay the production of an appeal response for 12 months.
So as SilverDJ has said, these small businesses are either forced to close voluntarily or subjected to liquidation by the ATO.
The GST "gold scam" was a real thing, but it has absolutely nothing to do with PB. The ATO are hugely embarrassed that they lost close to a Billion dollars, and they are looking to deflect attention elsewhere.
South Gippsland Bullion and Perth Bullion are merely scapegoats in a childish attempt at covering an embarrassing regulatory fuck up.