It's pretty obvious why they'd sell their shares, they're trying...

It's pretty obvious why they'd sell their shares, they're trying to get their funds back. If you're a mining company that's just purchased a project and have millions sitting in shares of a company you no longer have any connection to (and clearly don't care about sinking the price of in the short term at least), wouldn't you want to untether yourself and get as much of your capital back as quickly as possible? They're not an investment manager or fund, they have no business holding shares in another listed company for anything other than acquisition purposes.