Ann: Notice of Long Equity Derivative Position, page-5

I don't think there's necessarily any squeeze.
As I understand it swaps are off (ASX) market over-the-counter agreements to trade stocks. Because they are not on the ASX they don't show up in the counting. When they come into effect as trades, they do appear on the register. In this case the swap was the way Old peak substantially exited its position without us knowing by triggering the 5% treshold notifier till now.
I'm no expert on it but I know a fund manager I hold uses them as a preference, ostensibly to not telegraph their moves.

All IMVHO.