Crown prosecutor Louella Dunn said if the charge had been before the sentencing judge in August it would have made little difference to the final sentence of 26 months.
"If this was a stand-alone charge it would clearly warrant a prison sentence, with him being a priest offending against a young boy but given the lapse of time the Crown would say an eight to 10 month prison term, but to be served concurrently."
She said the offending came to light because of the publicity surrounding his sentencing earlier this year.
Brown's lawyer Mark Sturm said he didn't take any issue with the Crown's stance, but his client now wanted to move on.
"He is anxious to put the unhappy matter behind him both for the victim's sake and for himself.
"He is a man who has had a spectacular fall from grace."
Brown had not reoffended since he was first released from jail in the early 1990s.
Sturm said there was "room for optimism for the defendant when released that he will lead an offence-free life".
In sentencing him to the concurrent prison term, Judge Cocurullo told Brown that it should not detract from his "very serious offending".
The offending had a dramatic affect on the victim's relationships.
Convicted paedophile
It is now his third jail term for historic offending against young boys.
Brown was first jailed in 1990 after admitting molesting young boys while he worked as a priest in the Catholic Church around Hamilton and Auckland in the 1970s and 80s.
He was then jailed for 26 months in August after admitting four representative charges of indecently assaulting young boys during the 1970s.
Those victims were a 9-year-old altar boy, a 16-year-old whose dad had died and mother was dying of cancer, and a 6-year-old orphan.
Two of the boys were living in an Auckland orphanage, another was at home with family but attended the same church where Brown was a priest in Hamilton.
Brown had been living in Auckland after being released from prison in the 1990s after serving 15 months' jail for offences against young boys, before a second lot of charges were laid last year.