From the Australian slang dictionary:

Butcher : small glass of beer in South Australia – From the theory that a butcher could take a quick break from his job, have a drink and be back at work

I was unable to find a quantity of drink called “hacker”. Beer and computers don’t mix? Perhaps “Give me a hacker” doesn’t have the right ring.

Speaking of safety, this word reminds me of the old joke about the butcher that backed into his meat grinder…got a little behind in his work.