The rule of Law is paramount here, no matter how desperate CASA might be or how damning the suggested footage is, the real position is the High Court will be asked to test and interprate the Law.
My bet is they will stand with the owner of the footage, not accede to populist opinion but uphold the rights of the owner.
Without mounting a formal legal argument here there are authorities that in the normal course of argument support this position.
Possession is a powerful position.