A zookeeper has been hospitalized after a tiger (no details of individual name yet) caused scratches and puncture wounds: No Cookies | The Courier Mail
This article Tiger attacks keeper at 'Crocodile Hunter' Steve Irwin's zoo - BBC News (where I saw the tweet) says in part "9News quoted ambulance authorities as saying that they received word the keeper had "suffered puncture wounds to his left wrist and forehead... one of those wounds is not considered serious, but the other is more significant"" Terri Irwin's tweet says the tiger "scratched a keeper".
the Courier Mail article in Jabiru96's link has been updated: No Cookies | The Courier Mail There's a video on the link as well.
It never bodes well when a zoo tries to play down any incident, a scratch and a puncture wound are two different things in my book, one is from claws the other from teeth. I can understand the wish of zoo staff to interact with an animal I myself would if i where a zoo keeper but there are limits and I don't think human big cat contact can ever be safe long term. Especially solitary cats such as tigers, if they smell a rival as one of the above reports claim, natural instincts will kick in and that would be too horrible to think of. The reference to domestic cats made me smile, A report in our UK papers before Christmas stated that the domestic cat is "really out to kill it's owner" I didn't read the article but I'm sure it will be on line if any one wishes too.
I personally wouldn't enter an enclosure with any animal that could kill me (ie. orca, bear, big cat etc.). At the end of the day, animals are not rational and do not know or care of the long term consequences of their actions, nor could they be expected to. If a domestic cat bites or scratches it's owner, at most it will hurt like hell, if a tiger bit it's handler, it could cause fatal injury. However, this is my opinion and there are many people more knowledgeable than myself in the husbandry of these animals that are willing to take the risk of open contact. As a result, these animals live less natural, but perhaps more stimulating lives than those confined to their enclosure all day, not to mention the increased interaction with visitors which increases the profits for conservation (people paying to do encounters).