The zoo failed miserably. If the tiger got out after an earthquake or a tsunami, that would be forgivable.
But they fail to protect their patrons from enraged animals? That could be, and may be, considered criminal negligence.
The zoo was arrongant enough to try and handle the situation themselves, keeping armed police oficers outside the zoo for six minutes before they were allowed to come in and ultimately rescue one of the brothers.
The wall was too low. They had many reports over 40 years of tigers jumping the moat. They delayed the police rescue of a victim.
The zoo will pay big and some of the officials may even have charges filed against them.
I wonder if the slingshots were a type liberal 'throw-down' weapons. ;^)