The first thing that occurs to me is that the cracked glass could be dangerous and you need to get it fixed ASAP.
After that, I’m pretty sure that balcony door glass is supposed to be higher grade than window glass so it may be that this is a defect in the door. Check with your building manager/ strata secretary to see if this has occurred in any other apartments.
The balcony door will be common property so the Ownerrs Corporation (body corporate) need to fix it first and start looking at whose fault it is later.
When it comes to the “he said/she said” and finger-pointing, unless you can prove that it wasn’t you, they and the landlord are entitled to assume that it was.
You can only hope that they have landlord insurance or that the Owners Corp just claims against its insurance.
But, once again, the priority is to get it fixed and that means talking to the building manager or strata manager or committee secretary and only then worry about who pays.
One other thing – do you have permission to have the dog from the landlord and/or the strata committee?