Sydney Airport complaint: Rude staff

On 11 July 2020, around 9pm at the custom area . After checking in my luggage, I queued and waiting to get my passport chopped. I was flying from Sydney back to Malaysia. At the customs , I helped a Chinese man that was having some language barrier. This particular officer was very rude to us . He was quite big in size and have a dark skin tone . He began to loudly and rudely telling off the man that he need to get out as he cannot fly out of Sydney while holding a permanent residency. He then looked to other people who were queuing as if he wanted to find consensus from them and said ,” Can you believe ?? He doesn’t know English and still have a permanent resident ?”. The officer continue to be impatient towards him and wanted him to get out of the custom despite him having an approval letter.
Then I went and helped the man . I told the officer his situation and explained to him . I even showed him the approved letter. However, this officer is really stubborn. He keep asking me Why was I helping this man, he can’t speak English and he does not deserve the PR ….instead of solving the problem. This was way out of the matter! It is not the concern ! Poor man just want to get out of the country and go home!!
He tried intimidated us and humiliated us infront of so many people. Other officers stood by until one officer actually came up and asked us if he could help. Turns out , he knew how to speak Chinese ….In the end , the Chinese man get to go through the custom and get on the flight. There isn’t any problem to begin with but your officer won’t even listen to us explaining to him in ENGLISH. He just wanted us to go away and not bother him..