When removing your neighbbours trees is legal?

I read in yesterday's paper of the outcome from the court case between Unley Council and persons who had removed part of two trees in Commercial Rood, Hyde Park. Council was sure  legislation would not allow the removal of a neighbours tree without their consent and without Council approval. Nevertheless, The ERD  Court found last week that they could. At any time the removal of up to 30% of  a tree canopy is legal if the tree has dead wood, unsafe branches, etc that need to be removed. You can see in the photograph that the trees were cut off at 6 metres above the ground! I find it difficult to conceive that this is not more than 30% of the crown. And yet the judge found that he could not make a Beyond Reasonable Doubt decision that this was the case. This legal decision has cost Council considerable money in the hope of protecting trees in the council area but has now left all trees at risk.