California's Division of Occupational Safety and Health blamed the zoo for the assault and imposed an $18,000 penalty. A medical claim filed against the city by the keeper was denied, the AP said.
The tragedy highlighted the dangers in dealing with wild animals in captivity, but animal expert Jack Hanna said people should not be afraid to visit a zoo.
"I'd be [more] worried about getting in a car," said Hanna, the director emeritus of the Columbus Zoo and Aquarium. "A zoo is one of the safest places in the world to go to."
Hanna said on "GMA" today that about 99 percent of zoo animals have been born and raised in captivity, adding it is important to help keep the tigers and other animals from extinction.
"It's not like we're taking animals out of the world and putting them in the zoo," Hanna said. "San Francisco is a great zoo. These animals have the most phenomenal care."
Hanna acknowledged that people still have to be mindful the animals retain their natural instincts.
"A wild animal is like a loaded gun. It can go off at any time," said Hanna. "They are wild animals. They are very powerful animals."
"People have to understand," he said. "You can't do anything about this. That's there natural instinct."
The San Francisco attack is the latest in several high-profile incidents in recent years. In fact, several assaults have made headlines this month.
Earlier this month at a California animal sanctuary owned by actress Tippi Hedren, a tiger critically injured a 40-year-old worker when it repeatedly bit him.
Also, a tiger attack at an Indian zoo killed a 50-year-old man, after tearing off his left arm as he tried to take a photograph of the animal in its cage.
In November 2006 at Sea World, a killer whale attacked her trainer and pulled him underwater during a show.
But, tiger attacks aren't the only ones to reach the headlines. In 2004 a gorilla attacked a 3-year-old boy at a Dallas zoo, when it escaped from captivity and went on a rampage.
Even the most highly trained animals have attacked, like in October 2003 when Roy Horn, of the famed Siegfried and Roy duo, was attacked by a tiger during a Las Vegas show before a live audience.
The unprovoked tiger dragged Horn by the neck off stage, leaving him with massive blood loss and severe injuries.