Just found this little trap in the ANZ plat, regarding coverage for additional travel and accommodation expenses:
"In addition, if during the period of cover available a disruption to your journey arises from:
• your scheduled or connecting transport is cancelled, delayed, rescheduled or diverted because of a strike, riot, hijack, civil protest, weather, natural disaster or accident affecting your mode of transport;"
That's my bolding and it effectively means that you are not covered for other reasons, for example say, the plane has a mechanical fault. That's happened to me in the past causing a 24hr delay and about a grand in losses and my claim (with a paid 1Cover policy) was denied. TI policies with that exclusion are useless, unless of course it's not an issue if you're delayed etc because your plane has a mechanical breakdown. The airline will hand out a 'letter' describing the circumstances of the delay for you to give to your insurer.
The Amex Explorer specifically includes it (mechanical breakdown) as a covered event.