I am the owner of the net business in question.
I would just like to say that we have been operating in Australia since 2011. We have sold hundreds of our net kits to clients all over Australia and we never have had one complaint. There has never been any issues with the waterproofing of any building new or old. Not one issue, ever. I am sure the buyers would have contacted us if there had been.
This product is sold worldwide and to my knowledge, there has never been an issue with waterproofing or damaging to a building apart from the holes on concrete.
The system was installed by an Australian licensed builder and he is very competent at his job.
The screws used are stainless steel 6G 1 1/4″. Once the system is removed, after a few years, the screws are removed and the area in patched up.
I think a comment from Lady Penelope gives a lot of food for thought for this Strata. If this goes to the tribunal, your names will forever be remembered as the people who think the aesthetics of a concrete block should be put before the safety of young children. It is not a great way to be remembered….