The appeal was heard by Justices Jayne Jagot, Alan Robertson, John Griffiths, Debra Mortimer and Richard White, who will give their decision on the appeal after a two-week adjournment.
FMG is appealing the Federal Court Justice Steven Rares' 2017 ruling that awarded the Yindjibarndi exclusive Native Title rights over 2700sq.km of land just north of Karijini National Park that also hosts FMG's Solomon Hub.
The Yindjibarndi have been at odds with FMG for almost a decade over the miner's lack of engagement with them regarding development of the mine, and the lack of royalties and/or compensation.
The Yindjibarndi first lodged their Native Title claim in 2003.
When handing back the land at a ceremony at Millstream Chichester National Park last year, Rares said the Yindjibarndi people not only possessed today, but also have continuously possessed - since before the British Crown claimed sovereignty over Australia - specific Native Title rights and interests in the claimed area that have not been wholly or partially extinguished.
In light of the ruling the Yindjibarndi promptly lodged a compensation claim against FMG.
At the time, Yindjibarndi Aboriginal Corporation CEO Michael Woodley said exclusive rights meant more substantial rights, meaning that matters of a compensatory nature could be seen as a better opportunity legally.
The momentous occasion was celebrated by the Yindjibarndi, however, their joy was short-lived when FMG appealed the ruling.
According to FMG CEO Elizabeth Gaines, FMG was challenging the exclusivity of the rights, not the Yindjibarndi people's connection to the land.
"We think the concept of exclusive title is significant and that is why we are going down this path," she said.
"We have been very consistent with our position during the original trial and we obviously welcome the recognition of Yindjibarndi Native Title."
Gaines said the appeal was not an attempt by FMG to minimise the financial impact of Native Title.
"It is less about cost, less about the financials, it is more about the ability to undertake investment on that land - whether that is in resources, agriculture or in tourism - if you have a party that has exclusive possession," she said.
Woodley said the appeal could always backfire, as the size of potential compensation payments from FMG could be affected by whether the Yindjibarndi were deemed to have "exclusive" or "non-exclusive" Native Title rights.
"To our belief mining and exploration and other projects still can happen," he said.
"What we are saying is the exclusivity rights mean if no-one engages with the traditional owner about those activities, then the liability for you becomes a greater risk because of that group holding exclusive rights rather than non-exclusive rights."
Woodley said the Yindjibarndi had a fantastic relationship with every other proponent that operated on its country, except for FMG.
The group signed a land use agreement with Rio Tinto in 2013 to allow for the passage of railway lines for the Koodaideri I project, and it also has land access agreements with companies linked to New Zealand's Todd Family, who are developing Balla Balla.
The group has also been in contact with Hancock Prospecting, who has an exploration licence over some of the affected land.
The Federal Court hearing lists Georgina Hope Reinhart and Hancock Prospecting as fourth respondents to the case.
Woodley said the group did not have a land use agreement with Hancock Prospecting at this stage, just a heritage agreement to assist it with its exploration licence.
"They [Hancock] have also made it clear to us that if they were to mine on our country, they'd be happy to fall in line with an industry standard agreement and we can only take their word for that and we have no reason to doubt them on that front."