Susan Mouat admitted to police in October last year she pushed her husband to get him to leave the house, and that caused the fatal fall.
In the Court of Appeal in Wellington this afternoon, Susan Mouat's lawyer, Russell Fairbrother QC, said she had been pushing him so she could close the door and return the house to "peace and quietness".
He said Susan Mouat was an alcoholic and had been two or three years sober at that point, and was under the impression her husband was too when he came home drunk that night.
Fairbrother said the appeal was on the basis that the starting point for sentencing was too high.
"This wasn't a case were you could assess a starting point by looking at comparative cases. Really, one has to, with respect, look at the actual fault of the appellant on this occasion.
"My argument is the push itself could be regarded as relatively benign . . . the push, along with intoxication, has the element of danger which warranted a manslaughter charge."
He said both parties were in a familiar and "non-hostile" environment and that it was unfortunate Bruce Mouat had fallen on to concrete rather than the grass nearby.
Susan Mouat's fault was in not factoring in her husband's intoxication when she pushed him.
Fairbrother asked that a sentence of community detention be imposed instead.
Crown lawyer Charlotte Brook said an error of law needed to be established to allow an appeal, and while the sentencing was a difficult one, it could not be said that the judge made an error.
She said the pair had argued inside the house - during which time Bruce Mouat fell over a chair - and the push was one to deny re-entry to the house after he had agreed to leave.
Susan Mouat could have been "under no illusion" as to her husband's level of intoxication.
She said the sentencing judge correctly assessed Susan Mouat's culpability, and the starting point was "unimpeachable".
The sentencing judge had found a term of community detention would not be enough to deal with Susan Mouat's rehabilitative needs. She had admitted to a probation officer that she had started drinking again.
The judges reserved their decision.