It does seem like the regulations need to be tightened up. I would expect that people in the zoo and wildlife conservation worlds are looking at that - no one is happy about what happened here.
But also: while I don't support the public shaming of the parents or anyone in this situation, I do think that someone in a guardian role of a young child in a place like a zoo, should be charged with a misdemeanor and fined if the child gets into an animal enclosure. Unless there are extenuating circumstances (such as crowd confusion resulting from a prior emergency), or a failure of the enclosure or the zoo staff (like leaving a gate open - I doubt that happens often). It shouldn't be a matter of debate. You have a child under your supervision and he gets into a place that takes some doing to get into, and some negligence on your part? It shouldn't be even a question that the parent gets charged with something. But it's not a felony - it's a mistake, of negligence not intent. In this case it's a terrible, tragic mistake that caused the death of a beautiful animal (and an endangered species that was in a supposedly protected location, which makes it a thousand times worse than other, more general animal deaths). But let's not forget that it was caused by a mistake - vs. the many intentional deaths that happen all too frequently. I think people should focus their anger and energies on the people who kill endangered and threatened wild animals by intent (such as poachers and trophy hunters).
But anyway, thanks for posting this point of view.