"It seems to be the case is essentially one of credibility and reliability of the witnesses."
The Crown argued the boy, who is now in his mid-teens, gave consistent evidence and was backed up by what others had to say.
The Crown also said texts between the boy and the teacher prove a relationship and if the jury found the teacher sent the messages, it was "overwhelming" evidence of what took place.
The boy wouldn't properly be able to understand or knowingly give consent to sexual activity, the Crown argued, and jurors should reject the teacher's evidence.
The defence said nothing inappropriate ever happened and there was no physical, medical or financial evidence to suggest otherwise.
The teacher admitted staying a night at a motel on the Kapiti Coast in 2014, where the boy said the pair had sex, but the defence said the teacher was there alone and only she was captured on CCTV footage.
The defence cast doubt on the boy's testimony and that of other witnesses, saying they'd previously told lies. It also said the police investigation was deficient, with four or five officers in charge.
Justice Woolford said the boy was a pupil at the school the woman taught at.
"Was [he] in a position to give consent in these circumstances, true consent? Remember a person does not consent to sexual activity just because he or she does not resist."
The judge said although the teacher gave evidence in her own defence, she didn't have to prove anything and it was up to the Crown to prove its case against her.