I'm a filmmaker and reading that all I got was marketing spin - Hot damn, we're so awesome because we spent time to train up REAL deers to do what we want!
Given that the world isn't so fussed anymore about CGI, hell 3D isn't taking off the way they thought it would, creatives are just looking for something 'unexpected'. Most people assume TV adverts that have such a big non-human 'animal cast' would be CGI. Due to cost, availability and efficiency... then they think about animal welfare later, because there are loopholes you how to jump through as a filmmaker when dealing with living non-human animals. It's not grab a animal and do what you please in Western countries. At least that's what the legislation available is suppose to prevent.
Clearly Tooheys thought they'd feel all special by putting deers in an unnatural environment. I haven't got enough information to really make a proper judgement if from training to completion of the project caused suffering of the deers but I'm still glad I don't drink Tooheys. They taste crap for one.
Oh "deer!" I thought it looked pretty real at first and then convinced myself otherwise so I felt better about it. A pretty visually stunning ad but could have had the same effect without using animals. Sad world.
Bit late on jumping into this conversation but just wanted to clear any misconceptions up.
My partner worked on this ad and I can tell you there were real deer used in the filming but mainly CG (computer generated) deer.
So please continue to give the kudos and like this ad because it looked realistic yet mostly wasn't! And just to note, the deer in the apartment are some of the CG ones
on our farm 
