My boyfriend was in a small driving collision in Brisbane last night, it was legally his fault, there isn’t much damage to the other car but a few marks. We are leaving Australia in 2 weeks, what happens if the other driver makes a claim against us and we leave Australia without paying? We are on working holiday visas and literally have no money left so just want to know what the consequences would be.
It'll depend on first, whether or not they raise an issue. If not, all good. If they do, however...
Some countries work with each other if you've broken the law, so leaving may not help you avoid it, and may just make it worse for you. You'd also potentially have trouble if you ever wanted to come back to Australia. Also they can share the black mark against you with other countries, as well as you having to declare if if Australia bans you for such an activity.
Some of these might happen, and none might happen. But you should pay for it. Firstly, it's the right thing to do, and secondly, you never know what you might want to do in the future that could be affected by the unintended consequences / problems you might cause yourself by skipping the country. And as the world becomes a more and more connected place, the risk you run only increases.
If your boyfriend had the appropriate driving licence and insurance to drive the car, whether through eg 3rd party cover on a private car via the owner’s insurance, or rental company insurance, and he has
a) notified the owner and insurer/rental company of the incident; and
b) exchanged contact and insurance details with the driver of the other vehicle
I think you should be safe to leave Australia knowing that in case of any claim the matter can be settled via your respective insurers.
However, it would be wise to check official guidance for visitors on what to do if you’re involved in an accident during a stay in Australia.
As other answers have indicated, what you should not do is leave without making proper arrangements to deal with a claim if one is made.
If the accident involved a hire car, the hire company will have enough information about you for the police to trace you in your home country, eventually.
One of my work colleagues in the UK took a vacation in Australia, and unknowingly was picked up by a speed camera for exceeding the limit in a hire car.
He received the paperwork requesting payment of a fixed penalty fine, or a court appearance in Australia, at his home address in the UK about 8 months later. There was sufficient information about the time and place of the incident that he didn't have any doubts that he had actually committed the offence, and it wasn't either an administrative error or a scam.
He simply paid the (small) fine by credit card, and that was the end of the matter.
If the OP failed to follow the Australian procedures for traffic accidents (I don't know what they are, but for example stopping after the accident and exchanging the legally required information with the other driver, etc) this may escalate into a court case for the legal issues as well as the insurance company wanting to recover the excess payment on the hire car insurance. If the bureaucratic system has to kick into action for some reason, the marginal cost of "ticking all the boxes" for every possible violation associated with the incident is small, so that is usually what happens!