Maybe Singapore is too safe
As someone who lived in the US for quite a while, this whole uncle patting head and getting assaulted incident would not have happened there. Why? Because firstly, no one dare to approach a small kid and touch them in any way, cause maybe the parents have gun and will shoot you. Next, no one will dare to throw an old man to the ground like that, because maybe his family will have gun and come shoot you. Everyone will mind their own business, because any small thing can end up with someone pull gun and shoot you. One of my friends once got punched by homeless, when the dad found out, he flash his gun and said if he were there, he'd have shot the motherfucker in the head.
The fact that we got so many idiots debating, trying to argue that it's okay to shove someone like that, just shows how pampered they are to live in a relatively safe environment. A good father who is trying keep family safe overseas, will never try to escalate, cause who knows if they will react back and shoot your family. What these idiots haven't consider is -- what if the elderly man is actually a siao lang? Maybe you shove him, he pull knife and slash your daughter? This is why, even if we assume the pat was malicious (which it clearly wasn't but wtv), the appropriate response should always be deescalate and escape or leave the situation, not escalate. This is why we can say the australian guy is a bully. He knows the poor elderly man won't fight back, especially in a "safe" country like Singapore. If same thing took place in Texas or Mexico or India or whatever, let's see if this father still dare to start a fight in front of the daughter.