Hong Kong was broken off of China so that the British could push heroin opium on Chinamen. It's a laugh that westerners think they still have some colonial claim at what goes on in Hong Kong, based on their old drug pushing operation.
Unless newborns start living into their 130s no one alive today will witness it.
You can’t “fast-forward” and erase 156 years in a few decades.
This is not evidence of anything and I think this is quite irrelevant here.
The main issue is not the length of the British "occupation", it is the Chinese political division that has existed since the Civil War. Many in HK (like in Taiwan) fled the communists and the others moved there during "old China" times. The issue is opposition to communist forces.