Jaws dropped following last month's news that the Tax Office would be permitted to continue with its crusade to stamp out split, or linked, loans.
"No one thought that the ATO would be granted special leave to appeal to the High Court," says Peter McDonald, the national director of Taxpayers Australia.
Split loans are offered to home owners with an investment property. The one loan is split into two separate accounts - one for a home loan and the other for an investment property.
The borrowers then direct all repayments to the home loan account, while allowing interest on the investment property account - which is tax-deductible - to compound.
The Tax Office says the primary objective of these loan structures is to avoid tax, a view rejected by the Full Bench of the Federal Court when it ruled the tax deductions were permissible in August last year.
This legal skirmish will continue for at least another six months, leaving existing split loan account holders in limbo.
"There are a number of people who used these arrangements," says Michael Dirkis, tax director of the Taxation Institute of Australia. "It's a classic example of where the commissioner dropped the ball and there has been uncertainty ever since."
However, he says the overriding priority for people with split loans should be to safeguard their legal position.
So investors already wrangling with the Tax Office on this issue should continue lodging their claims - and then lodging objections when their claims are predictably disallowed - in order to protect their interests should the Tax Office challenge ultimately fail.
People who have just entered into split-loan arrangements should also claim the interest deduction in their returns, while being sure to tick the box that indicates they're making a ruling request - to notify the commissioner that you are making a claim that will be disallowed. "Because of our system of self-assessment, what you put on your return tends to be what is allowed," says Mr Dirkis.
"The last thing you want to do is slip (the claim) into your return and get a refund which you might have to repay, with interest of 11.9 per cent, somewhere down the track."
But Mr Dirkis says every situation is different.
The most important thing is to seek proper advice from your accountant or tax agent about the steps you can take to protect your position.
