The “As God is my witness, I thought turkeys could fly" defense only works in situation comedies. In the real world safeguards are supposed to be in place so that the animals cannot get out under any circumstances. The fact that the wall does not meet Association of Zoos and Aquariums standards means the San Francisco Zoological Society is so, well, you know.
No sympathy for the punks on my part, but what if the tiger had decided one day to take a four year old, just because she could? From the facts we know now she could have any time she wanted, she just never was motivated.
Exactly, the motivation of the animal is irrelevant. Suppose the boys were just wearing the wrong color on the wrong day.