Prosecutor Erin Woolley said the woman didn't positively consent which is required under New Zealand law and the absence of protest wasn't enough.
During the trial, the jury heard on the morning of Auckland Anniversary Day 2016, Briones took a CD to the woman's house. She invited him in for a coffee so they could enjoy it together.
Shortly after he was inside, he allegedly told her to sit in her La-Z-Boy rocker armchair and moved her walker out of reach and touched her breasts.
The woman said she was unhappy with what happened but because she hadn't had her medication yet and her mind "wasn't there at the time".
"I thought he was a friend and he took advantage of me," she said giving evidence.
After rubbing her on her rocking chair, Briones allegedly then led her to her bedroom.
There they lay on the bed together and kissed before he sucked her breasts and rubbed her genital area, the prosecutor said.
"He then told her, 'No one needs to know about this'."
To make him stop, the woman told him she was bleeding and her sister was coming over shortly.
Meyrick said the woman wasn't credible because when she was on the stand she was adamant she didn't wear skimpy clothing around the complex.
However, three witnesses testified that she did.
"She's not that simple, ladies and gentleman. She doesn't have that much of a disability. She knows what she was saying. She knows what she was doing," Meyrick told the jurors.
"She's not confused, she's not mistaken; she's lying."
The woman took off her own dress, lay on the bed naked and kissed Briones' back, Meyrick said.
"But there are positive things here; she took off her dress, lay on bed, kissed him. You can't get more positive action than that."
Meyrick declined to comment on the verdict on behalf of his client but said he didn't think reporting of the trial had been honest or fair.
