With all the money printing , pressure will be on all countries...

With all the money printing , pressure will be on all countries including Australia and US in terms of their currencies value decreasing relevant to gold, so the gold price will rise in both currencies regardless of the exchange rate, so in my opinion David's argument should be that with a stronger AUD we may not see as big gains in the gold price compared to gold companies with US dollar pricing . So it is prudent to hold mining companies that have US dollar cost exposure and is why I hold WAF and RSG and TRY.
I also hold RMS and SAR as a hedge should the US dollar is stronger. But I should add that if your cost is in US dollars , so are your profits and same applies to AUD , so costs can be higher in reality , but so are the profits or alternatively costs can be lower but so can profits in real value.
Either way the real value of gold is going up because money printing = inflation and inflation means reduction in purchasing power.
More money in circulation relevant to an economy's production staying the same means reduced purchasing power as there are more dollars for every part of production, so prices increase.

Christopher