1.) Just wearing t-shirts flying over that terrain was just plain stupid. Doesn't exactly strike me as being prepared for something going wrong either.
2.) Obviously white-out is a common hazard in the Antartic. Don't know if they'd adequately researched and prepared, but they didn't or couldn't cope with it when it happened. Had they any experience of it? London-Sydney was unlikely to include those conditions
3.) Two relatively inexperienced pilots, both PPLs without an IR between them, set off to fly over the South Pole. If they'd made it without incident it would have been lucky. They lucked out. The good thing is they lived to tell the tale.