Other things are more relative
The US helicopter (and most other aviation) accident records are better than the Aus even tho Aus has no snow or ice or tornado's or hurricanes (one force 3 Cyclone Tracy every 30 years does not match 30 force 3 hurricanes every year), no microbursts, no smog, no whiteouts and no mountains (7,000 ft is just a big hill). There are more aircraft in the Los Angeles basin than in the whole of Aus yet Aus has more collisions.
Why is the US safer - probably because they do not operate under the massive illusion that they are the safest in the world and/or that their biggest airline has never had an accident.
Complacency is a killer