yes but he would obviously short cwn using a front offshore...

yes but he would obviously short cwn using a front offshore company, obviously not one called james packer holdings,lol but one called eg. cayman financial capital pty ltd.
In big business there are NO morals, everyone knows that, you push the boundaries of LEGALITY as much as you can to make the biggest profits , that's business school 101.

Also JP by shorting cwn to $8 wouldn't be destroying shareholder wealth, because it would just be a ST exercise, just so he could get cwn down to $8 or so for a couple of months, than buy in big at say $9.50, than go long.
but who am I to teach a billionaire what to do