She added that Evan's claims remain and that her client will continue her fight in other venues.
Assistant District Attorney Joan Illuzzi-Orbon told the judge that prosecutors would not oppose dismissal of the count in the case involving Evans.
A message left on a phone used by the detective in the past wasn't returned.
Weinstein appeared in Manhattan Criminal Court on Thursday morning as Judge James Burke chose to dismiss count six of the eight-count indictment against the 66-year-old film producer.
The woman also told the detective - identified by Weinstein's lawyer as Nicholas DiGaudio - that sometime after Evans' office meeting with Weinstein, she suggested what happened was consensual, according to the letter.
Evans denied her friend's account and insisted that she was forced to perform oral sex on Weinstein, the court filing says.
The New York Post, never known for its restraint, blasted out a headline just before the judge dismissed the sexual assault count, wondering if the D.A.'s case is "in danger of falling apart". At the time, she was a 21-year-old student and aspiring actress. The D.A.'s office said it "recently learned" the witness" account was shared with police and that police "failed to inform our office of important account prior to the indictment in this case'.
She says Weinstein forced her into oral sex in 2004.
Storm Callum to BATTER Glasgow with heavy rain and strong winds
The main concern we are anxious about for the area is the amount of rainfall throughout Saturday itself. Last month, Storm Ali battered the country, causing two deaths and widespread infrastructural damage.
Samsung Galaxy A9 with quad cameras, 3,800mAh battery launched
The Samsung Galaxy A9 is set to go on sale in November this year starting at £549 - retailing over £200 less than the Galaxy S9 . Dubbed as the Samsung Galaxy A9 (2018 ), it comes with a total of five cameras- four on the rear side and one on the front side.
After an undisclosed security breach was revealed, Google+ will be shutting down
To make matters worse, Google decided not to share knowledge of the data breach when it was discovered in March. Users who connect third-party apps with Google will get more granular control over what data gets shared.
Prosecutors said the police detective didn't share any of that information with prosecutors and urged the woman not to reveal details, saying "less is more", and that she had no obligation to co-operate with investigators.
Weinstein's attorney, Benjamin Brafman, argued that the charges be dismissed due to Evans previously describing the sex act to a witness as consensual.
Harvey Weinstein appeared without handcuffs in New York Supreme Court this morning and even flashed a faint smile, a big change from his previous sober and shackled appearances in his sexual assault trial.
"According to the Witness.the Complainant [Evans] told the Witness that.the Complainant had gone to the defendant's office, where the Defendant told her, in substance, that he would arrange for the Complainant to receive an acting job if she agreed to perform oral sex upon him".
The accusations led to the #MeToo movement in which hundreds of women publicly accuse powerful men in business, politics and entertainment of sexual harassment and abuse.
The collapse of part of the case against him could mean trouble for the prosecutor.
In the months after The New York Times and The New Yorker began publishing stories about Weinstein's interactions with women, activists pressured Vance to bring charges as dozens of people came forward with claims of sexual misconduct against him.
Out on $1 million bail after having entered a not-guilty plea to the first round of indictment and surrendering his passport earlier this year, Weinstein was last in court July 9 to enter another not-guilty plea.