PS - IJ - the data on that site seems to stop at 16th dec in-line with ASIC's data, so it is 5 days delayed. You can't tell from that site what is actually happening today. You can make inferences if one believes in a fundamentally corrupt and manipulated stock market as I do!
The 20m shorting friday was likely merely more shorting intraday into the close to get the lowest possible crossing prices.