you don't have to be faster than the bear, just faster than the slowest one in your group...I will point out one thing, "Survival of the fittest"
from a legal perspective, the zoo is f***ed. it's not "reasonably foreseeable" that the cat would be able to jump out of the enclosure, so it's hard to say that the youth are culpable for the incident. if you poke a bear with a stick in the wild, it's reasonably foreseeable that you'll get eaten. if you torment a wild animal in a zoo, it's NOT reasonably foreseeable that it will escape and kill you.
however from a personal standpoint, many of us are apalled by the thought of drunk, stoned teenagers standing on a railing tormenting a caged wild animal. it's not that I think that the teenagers SHOULD'VE been eaten b/c of what they did, but I have less sympathy for them due to their cruel actions beforehand, and a little bit of Schadenfreude in that they provoked a wild animal believing themselves to be superior (and safe) and ended up being neither.