My wife and I discussed this portion of the story last night, and I'm still of the opinion that bailey was not wrong. Seems to me, that there were lots of reasons not to off that animal immediately. She gave the owner time to correct the situation. She gave animal control time to correct the situation. These are reasonable, responsible things to do, but they both failed to correct the problem. Should she have killed the dog in front of the owner, like some hotheads have suggested? It's been my experience that people who enjoy owning a killer animal, are prone to throwing a few punches themselves. I think that directly confronting a person like that would indicate "a few screws loose."
The only other option that she was left with would be "kidnapping" the dog in order to take it to a shelter, or try to find a new home for it herself. But let's be realistic - No shelter would be able to adopt out that dog with its history. Euthanasia was in that animal's future, no matter which path Bailey chose.
You're right, the whole story is very disturbing. But the blame still falls on the owner who FAILED to be responsible with his dog. That dog should never have met the fate that it did, but it's not bailey's fault, even though she had to do the dirty work of pulling the trigger.