The young lawyers — all well above the legal drinking age — were given a glass of champagne as part of the celebrations.
"Congratulations to our 2018 law graduates," the post read. "This talented bunch was recently admitted to the bar — keep up the good work team."
However, in attempt to avoid negative perceptions of the event, the firm's marketing team decided to photoshop the drinks out of the photo after a discussion with others at the firm, news.com.au reported.
Simpson Grierson has since confirmed the image was edited to make sure the staff members' achievements was the centre of the attention.
The firm uploaded another image in its place. The original doctored image no longer appears on the Simpson Grierson Instagram page.
Poncho Rivera-Pavon, a human resources consultant in charge of law graduates and summer clerks for Simpson Grierson, said the decision to remove the glasses was made to keep the focus on the graduates' achievements.
"We're very aware of the media sometimes misconstruing things and making it look like it's all about the young lawyers having a drink at work," he told Newsroom.
"We wanted to make it all about their admission to the bar and how important it is for them, so we decided to remove the glasses."
He added that "recent reports of alleged misconduct at other New Zealand law firms" was a factor in their decision to edit the photo.
It comes as another New Zealand law firm, Russell McVeagh, was the subject to a damning sexual harassment inquiry which found it had struggled to promote and retain women lawyers.
"We're proud of their achievements and shared the photo externally, taking the champagne glasses out so the focus would be on graduates' awesome milestone and not about them having a drink at a work function," a Simpson Grierson spokesman told Stuff.
"By doing so we seem to have created the opposite effect, which was certainly not what we intended. We're sorry for any unwanted attention that our graduates received as a result.
"We asked our graduates if they'd prefer the photo to be taken down and replaced with an alternative, and several of them said yes."
