> this is what happens when you run a company with consultants...
It depends on the consultants you get. There are plenty of well known, well respected, network operating consultants in Sydney who learnt BGP in the late 90's and know the pain it can cause if it's not configured correctly when you're a small network connected to a big network.
All network administrators get lazy and all network administrators fuck up occasionally. The good ones suffer from enough oversight and management that they're forced to do changes properly (like making sure there are proper filters in place and they've been re-activated after debugging & testing). The old and wise ones know the value of doing network changes with rollback plans; or build their networks "like onions" so when you fuck up at the edge it doesn't crash your core.
This is exactly what happens when you outsource your network operations to the cheapest vendor; when you have minimal oversight and change management, when you're used to providing a "best effort service" without any financial penalties for non-performance, and when you're used to being the (second) biggest fish in a small pond.
It's also what happens when people like Bevan Slattery make network peering so easy that the current cohort of "network engineers" spend more time configuring BGP via web interfaces and checkboxes than playing spot-the-error in 100 lines of Cisco code - but again, that's on Optus for not vetting their network operators.
Anyway - speaking as someone who's taken an ISP offline while configuring peer routes before (at 2am, with a rollback plan in place) - the only thing that really surprises me about this is Optus's CEO resigning.
Back in my day the official response would be "Lolz. Sorry `bout that. It's a best effort service. If you wanted five nines reliability you shouldn't rely on only one upstream provider. As for you getting your money back... well, our SLA dictates a response time, which we met. The restoration time was 4 hours, but they're business hours; so our outage started at 5pm, but the SLA the clock started ticking at 9am we restored your service at 2pm the next day so that's 2 hours outside of our 4-hour SLA. That means you're entitled to a 2% rebate on your next monthly invoice."