Why the claims Genter just used the wrong letterhead are pitiful

The Herald reports:

The Associate Transport Minister will also be looking to spruce up her stationery to avoid confusion over whether she’s corresponding in her ministerial capacity or as a transport spokesperson for the Green Party.
The letter Genter sent to Transport Minister Phil Twyford in March this year regarding Let’s Get Wellington Moving has landed in the House again this week.
The biggest, and somewhat confusing, revelation to come out of Question Time today was when Genter confirmed the letter was written in her capacity as Transport spokesperson for the Green Party.

For days she’s been answering questions in the House about the letter in her capacity as the Associate Transport Minister. Not to mention previous answers to written parliamentary questions in that capacity too.
Today she said the letter “highlighted the Green Party’s position on aspects of the transport project”.
The water was further muddied when National’s Transport spokesman Chris Bishop asked whether or not the letter was sent on ministerial letterhead.
“As it happens I had only one type of letterhead but that is something I will be changing”, Genter eventually conceded.

Firstly that is incorrect. All MPs have unlimited supplies of standard parliamentary letterhead which they can use when corresponding as an MP.

Genter both used ministerial letterhead but also signed it as Associate Transport Minister. Yet she refuses to accept any accountability for this.

Contrast that to Nick Smith. Nick Smith in 2012 resigned as as a Minister. Why? Because he had written a letter of support for a friend in her ACC claim. And he wrote it on his ministerial letterhead, instead of his parliamentary letterhead. That mistake was enough to have him lose all his portfolios.

Genter however won’t accept any accountability for her actions. She wrote to Twyford as the Associate Minister on ministerial letterhead, yet still won’t release the letter,