"I misspoke" is becoming a very convenient way to say you were either lying or being honest about your true position on an issue. Luxon misspoke about wanting to dry-hump the US over Iran; Stanford misspeaking here about scare stats.
"misspoke" is just weasel code.

Immigration Minister Erica Stanford apologises after inflating overstayer figures https://www.rnz.co.nz/news/political/588661/immigration-minister-erica-stanford-apologises-after-inflating-overstayer-figures

Immigration Minister Erica Stanford apologises after inflating overstayer figures

The government has been accused of scaremongering about overstayer numbers after Erica Stanford told reporters there were "tens of thousands more" than she had expected last month.

RNZ
@paw While I generally agree with this analysis, in Luxon's case it seems possible that he just said something stupid without thinking it through. #Occam
@thomasbeagle Totally but that's kind of my point. "I misspoke" is such a benign, unaccountable phrase it detaches you from having to own the impact of your comments.
It's like saying "I'm sorry IF I offended you". It's not taking accountability for your words, it's avoiding the issue.
Luxon didn't misspeak; he had an unguarded moment when the mask slipped and he said exactly what he thought, and then he had to crawl it back.