Seems in a recent decision (Applicant vs Linfox Armaguard PTy Ltd) its ok in moderation. 

Whilst I don't agree that behaviour of the nature outlined in this dispute is acceptable at all, particularly when loaded firearms are present, it does spark the question of "When is what might be harmless bad language and mucking around step over the line into inappropriate behaviour?".

For me the answer is simple. It's not acceptable, and should not be condoned or ignored. In order to address bad behaviour in the workplace it is essential that policies and procedures be clear, concise, and regularly communicated to the workforce. 

To ignore due process, to be reactive rather than proactive, is to do so at your own peril. The above decision highlighted this.

Now the debate on this decision on other forums has been extensive, with varying opinions on not only the outcome, but also the impacts on other employers moving forward, having been debated at length.

But if employers are wanting their business to grow, and their employees to grow with them, then one of the first starting points must be behaviour.