They had multiple pathways. The top three destinations were Canada, the USA, and Australia. These locations offered a major benefit over the UK - they were on trade routes along which people from Hong Kong were already doing business.

Canada was particularly affected. It absorbed the most immigrants, they were a larger share of the population, and this was a major increase in ethnic diversity. The resulting cultural clashes were sometimes an issue. Here is one that literally doubled car insurance rates in British Columbia around the time I left.

Three cars, 2 in front with the left-hand car being driven by a Canadian, and the back car driven by a recent immigrant. The immigrant sees the opportunity to pass, swings out into oncoming traffic, and guns it. Leaving just a few inches of room. Normal Hong Kong driving.

The Canadian has no idea that this is happening until OMG I'M ABOUT TO BE HIT! The Canadian then swerves right to avoid the emergency, and hits the car on the right.

The immigrant drives off. Presumably wondering about these crazy Canadians who don't know how to drive.

Everyone involved behaved reasonably for how they were used to driving. But the combination worked out very poorly...