Firstly, I don’t disagree with anything Scotlandx has said below and if the decision is to reinstate the garden, the person who ripped it up should pay the bill (as outlined in the strata Act.
I would imagine that a half decent awareness campaign would make sure this person did not get the requisite 75 percent vote allowing them to annex the garden.
However, there is another possibility here and that is the establishment of a communal garden where residents can work together and collectively to create a communal vegetable and herb garden and literally enjoy the fruits of their labours. The GreenStrata website has a number of case studies on how this has worked in many inner city buildings HERE. It’s worth a look and may offer a non-confrontaiional compromise solution that works for all concerned.