 His business partner David Walsh believes that he does not owe them money as gambling on horse racing has never been a taxable source of income in Australia.Tax experts following this case have said if the ATO has now changed its position on horse racing gambling, taxing retrospective wins is unjust and imminent for a high court challenge and could potentially open up a can of worms for every Australian who has won on horse racing in the past.After months of debt claims by the ATO, a settlement was agreed with Zeljko and other members of the punter's club, late October 2012.