He wasn't ostracised, mocked or emasculated.
You could almost guarantee that's what would have happened if he had gone through this 30 years ago.
But attitudes are changing for the better and his candidness about mental health has been seen by many as refreshing, honest and brave.
Muller's admission may even be the final nail in the coffin for the hard-to-shake perception that men should be hard and unfeeling.
Mental health has been in the spotlight for a few years now; businesses are starting to explore ways to better support employees, schools are more aware of student wellbeing and money has gone into funding better mental health facilities around the country.
But it is still more socially acceptable for a woman to speak up about her mental health than a man due to societal gender roles which take time to change.
The undercurrent of toxic masculinity preventing more men from speaking up and getting the help they need is waning but it's still there in today's society.
Hopefully, with Muller joining other high profile men such as Sir John Kirwan and Mike King, more New Zealand blokes will realise it's okay to talk about their struggles.
Through their frank discussions, these men, along with others, will help to usher in a new way of thinking, a healthier approach to dealing with mental health as a man.
The flow-on effects of this shift in societal outlook will be huge. As more men feel safe to express their feelings, suicide will decline, family harm will decline, addiction will decline.
It may not happen immediately but if the public response Muller has received since stepping down is anything to go by, New Zealand is moving in the right direction.