Never heard of a theoretical liability. If you have rights and obligations for the area according to the declaration of division, you must ensure security. Or do you think your liability or building insurance will simply cover a personal injury, which is one of the most expensive damages? An expert will come out, see a hedge or temporary solution and say "no insurance coverage on our part."
Now you're already quibbling over words, aren't you embarrassed by that? What exactly does that bring you?
The declaration of division is, as far as I remember, to our advantage. If I recall correctly, we have the exclusive right of use, but no obligations. Sounds unusual, but that's how it is. That means we wouldn't even have to take care of maintenance, not pay for the outdoor water tap, etc. (which we are currently doing anyway). I then think we wouldn't be responsible for the security either.