HOW and WHY about Tiger's attack at SF Zoo.... Who's the victim?

Not sure if you guys heard about the tragedy at the San Francisco Zoo last Chirstmas, three young men were attacked by a tiger that escaped from its grotto, and one of them was killed, the other two injured. the tiger was shot by police on location.

One of the reasons that shocked the people in SF is that, HOW did the tiger come out? The tiger grotto is 31feet wides and 12.5 feet tall, and the cage at the back was locked tight so that it was impossible for the tiger to escape from the back. So almost everyone was surprised when it was told that the tiger jumped out from the grotto (no one confirmed it yet but then there was no other way out, so it was the most accurate assumption), even though by 12.5 feet, it is far shorter than the AZA recommended height of 19feet.

the other mystery about the case is WHY? animals at the zoo are affluently fed, so it is unlikely that they would escape to hunt for food. From the evidence discovered and reported, the most likely explanation is that the tiger was provoked, and obviously the young men were the primary suspect.

according to some news sources, the two injured victims, who were brothers, brought a slingshot to the zoo on that day, and an empty vodka bottle was found in their car as well. moreover, they refused to cooperate with the police and didnt tell what happened on that day, and they also refused to have the cellphone examined. some past record also showed that they were arrested by police a few months ago for intoxication and resistance against arrest, and they were scheduled to go to court this month for those cases.... Now they are hiring a lawyer to ask for compensation from the zoo....

To find out the truth (just a better excuse), or for some other  reasons, i actually went to the zoo last thursday when it reopened (it was closed after the accident until that day), and checked it out.

i talked to quite some visitors there and with no exception, all of them were sad about the accidents, but whats interesting is that ALL of them were sorry about the loss of the tiger more than the human victims, and most who are frequent visitors of the zoo said the tiger wasnt those aggressive type that would attack for no reason, and they tended to believe it was taunted somehow.. these people brought flower and stuff toy to mourn the tiger at the zoo..

i also went to the tiger display area to check out, it was closed due to the reconstruction (the zoo is working to raise the height of the grotto wall to at least 19 feet and add a glass wall), but from the other side of the display area, i kinda took a glimpse of it, and from what i observed, i was also kinda surprised how the tiger could jump up from the 12.5 feet grotto wall..if it really escaped from the front, it seems more likely that it jumped 31feet from the other side of the display area, rather than from the bottom of the grotto... though it was still amazing...unless it was seriously taunted, i dont think the tiger would be able to jump that far...

so after the tiger jumped out and killed the first victim just right outside the tiger display area, the other two victims escaped to a cafe thats about 5 mins walking distance away, and they were attacked by the chasing tiger there.. the lawyer of the two brothers claimed that when they escaped to the cafe, the staff there closed the door and refused to help them, letting them stay outside for 30mins b4 police came..which i guess was kinda hard to believe.

i tried to follow their escape route (as told by police), but then it only took  me less than  5 mins to get there, and imagine at that time both the brothers and tiger were running (i assumed, but even if they didnt, it was still 5mins), so how could they stand the tiger for 30mins without getting killed was really amazing!

anyway, that's just some of my thoughts and speculations about the incident.. i guess both the human and tiger killed in the incident were victims and the zoo should be held responsible to some extent..but whether it should be claimed totally responsible as the lawyer of the two brothers said is another story... (my friend said, the siberian tiger is endangered animal, its life is more precious....bad joke but true)...

so any thoughts?