For Phil Heatley's sake, let's hope the plonk was a pretty special drop. Using his taxpayer-funded credit card to buy a couple of bottles of wine during the Saturday night knees-up at last year's National Party conference could literally end up costing him more in lost salary than you pay for the best Chateau Lafitte.
Resigning from the Cabinet might seem an extravagant price to pay for a misdemeanour involving the grand sum of $70. More so when contrasted with ministers pocketing market rents on Wellington flats and houses they own while claiming thousands of dollars a year extra in parliamentary accommodation allowances by living in other properties. A rort is a rort, however you dress it up.
However, there are major differences between Heatley's flashing the plastic and the questionable payment of some housing allowances. The latter are within the rules; Heatley's purchase of wine fell outside.
Heatley claimed ignorance of the rules. That is hardly a defence. Regardless, it surely beggars belief that he thought it was okay to buy alcohol at a social function run by his own political party and expect the taxpayer to foot the bill.
Anyone who has attended a National Party conference knows the bill for the dinner is paid in advance - usually when registering for the conference in the weeks beforehand - and not at the dinner.
In contrast, drinks are bought from a "cash bar" which - judging from the credit card voucher - is where Heatley bought the wine for his table.
So why did he write "food and bev" on the chit when he was only buying alcohol? A week later Heatley signed a Ministerial Services reconciliation form which had the explanation for the $70-worth of spending as: "Minister and spouse - Dinner".
That form carries a declaration that those signing believe to the best of their knowledge that the form is accurate.
It wasn't. Heatley concedes that all this "could be viewed as an inaccurate representation of the expense". That is the nub of it. Heatley may be honest as the day is long. His sloppiness, stupidity, untidiness and carelessness - to borrow the Prime Minister's caustic vocabulary - has left open the door to charges he deliberately tried to mislead officials responsible for checking expenses.
That is why suggestions that Heatley's resignation over a relatively trivial sum of money sets a new benchmark for ministerial standards are misplaced.
It isn't the amount of money that is at issue; it is that the declaration was inaccurate. Its inaccuracy raises questions of honesty and trust that should never have to be asked of a Cabinet minister.
Rather than immediately sacking him, the Prime Minister intended temporarily standing Heatley down from his portfolio responsibilities. This was a compromise position which made allowances for human fallibility on Heatley's part, while at the same time calling in the Audit Office to run a fine tooth-comb through all the expenses he had claimed in the 15 months or so that he was a minister.
But John Key was seemingly gazumped by Heatley's desire to resign altogether. That is the unusual feature of this resignation. Usually the minister is pleading with the Prime Minister to stay in the job.
Key urged Heatley to "sleep on it" before handing in his ministerial warrant. Significantly, that gesture did not extend to refusing to accept Heatley's resignation. That is telling. It suggests although the Prime Minister is not ruling out Heatley's return to the Cabinet, there is not much optimism that the Audit Office probe will not reveal further shortcomings with the ex-minister's expenses.
Heatley's route back to the Cabinet will require that everything is squeaky clean. It also presumes he wants his job back. Heatley's statement about needing to spend a long time on National's backbenches suggests he realises that is not going to happen.