"No surprises"

Radio New Zealand this morning informs us that tens of thousands of beneficiaries have been under (and in some cases over) paid tens of millions of dollars due to a "coding error". In a way, this isn't really surprising; WINZ are relentless fuckups, and this is just their ordinary, everyday incompetence made systematic. What is surprising is this bit:

The mistake was discovered in September 2014 and was fixed a few months later, though Social Development Minister Anne Tolley was informed only in March this year.

So WINZ uncovered payment errors totalling tens of millions of dollars, which create legal liability and potentially require urgent legislation to "fix" (by pretending they didn't happen, of course), and they don't tell their Minister for six eighteen months? So much for the "no surprises" policy. I'd expect Tolley to be asking some pretty pointy questions of her Chief Executive over this - and perhaps demanding their resignation.

Correction: So, its even worse than I thought. How can a chief executive not tell their Minister about a spending problem totally tens of millions of dollars for eighteen months? Isn't that head-on-a-spike time?