Here's a story, the relevance of which should become clear.
Woke up morning after attending a non-public function because of noises outside, found pictures of me from the paper taped to my door. All the other pictures related to the article had names attached, mine didn't - photographer felt like asking everyone else, but not me.
Called up NewsCorp and pointed out it was not an open-entry function, that my permission had not been granted for publication, and that I was being harassed and at risk of harm as a result of my image being used (particularly as at the time I was on the run from a deranged ex). They pulled the photographer out of a meeting and he said 'it's a public place, so by being there you gave permission, gotta go' and wouldn't listen. However, my picture was pulled from the digital version and not offered on that site where you can buy 'selected' pictures from the papers.
Based on my experience, I suspect NewsCorp have a standing instruction to play fast and loose with expectation of privacy - and believe that being in a place that is public (a pub is, by definition, public, even when there are measures taken to prevent access to some parts such as security and ticketing) is enough to counter a reasonable expectation of privacy.
Similarly, the relayed events of 2012's Mad Monday would demonstrate that privacy at club events is not a given, and the general admonitions on Mad Monday behaviour would indicate that the NRL doesn't believe privacy at club events is a given... and all we need is for a NewsCorp lawyer to argue public interest before the DPP declines to prosecute. Whether it's a public place goes to whether a reasonable expectation of privacy can exist, and goodness knows there's enough out there about how NRL players are role models and how famous people are less entitled to privacy etc. that they can fall back on too.
Not to mention that each player would have to pursue their cases individually, and the amount of stress that would place on them for the next 1-2 years.