Ann: Production Update Q1 September FY21, page-10

I've said this before but Gwalia is not your average mine with constant, predictable output. The mine output is very lumpy (not linear) and highly interlinked with scheduling of other activities, partly because of the difficulties operating at 1800m below surface with a decline only (note the rock fall was on the decline so probably affected almost everything).

If an outage hits at the wrong time then there can be big variances in gold production, particularly since there is no stockpile either to fill the mill.

This was probably a 15-20koz shortfall in production vs original plan. I'm definitely skeptical they can make that up.