It was also necessary to take into account that some of the complainants were intoxicated at the time of the events, and that some had recalled memories at a later time. This did not discount their evidence, but it needed to be treated with caution, Peters said.
Jurors were told to put aside feelings of prejudice and sympathy.
"Judging is an analytical exercise. It is not an emotional one. We just need you to focus on the cold, hard evidence."
At the closing submissions, defence lawyer Warren Pyke asked the jury whether they could recall what they were doing 40-50 years ago.
"I doubt you can and I doubt these complainants could too. We need to remember that time does affect memories," Pyke said.
"This is an attempt to paint my client as an evil man who cannot control himself.
"One complainant described himself as having a very faint memory of the night, but somehow magically he recalls these sexual things? It's because it never actually happened."
Pyke told the jury to "be careful" when assessing whether the individual stories of the complainants add up.
"If you add up six flawed stories then you don't get one good story," Pyke said.
The 75-year-old ex teacher appeared in the High Court at Auckland before Judge Mary Peters.
Charges against Cave include sexual violation, indecent assault and supplying drugs to boys in Auckland and Hamilton. He has pleaded not guilty to all charges.
The alleged offences span almost four decades.
Crown prosecutor Jacob Barry, assisted by Belle Archibald, asked the jury to consider the position that the young victims were in.
"What on earth could have been going through the minds of these six young men as they have just fallen victim to their music teacher and friend Leonard Cave?
"This is one trial, four decades and six men with a tragic shared experience."
Barry said the Crown's case was not that Cave touched and abused every young male that he came in contact with.
"But he plainly had a type. Every one of these six complainants knew him through a teaching relationship.
"Cave was prepared to use his positions as a vehicle to prey on young men," Barry said.
"He didn't think that the rules applied to him. He believed he was beyond the rules. Well, the rules do apply here.
"Dilworth is like an island oasis. Children are plucked from a difficult life, to strive here, yet someone like Cave has taken advantage of this."