"Today, in open court, counsel for Donald Trump stated that the violation of the gag order was inadvertent and was an 'unfortunate part of the process that is built into the campaign structure,'" the ruling said.
"Given defendant's position that the violation was inadvertent, and given that it is a first time violation, this Court will impose a nominal fine, $5,000, payable to the New York Lawyers' Fund for Client Protection."
On October 3, Trump posted a comment on social media about the principal clerk and was asked to remove the comment; Trump indicated that he did remove the comment about ten minutes later, the ruling said.
In addition, Judge Engoron said that he placed a limited gag order on all involved parties, prohibiting them from publicly discussing any members of the court staff as they would be considered "inappropriate" and violations would potentially lead to significant sanctions, the ruling said.
However, Trump removed the alleged offending post on Thursday night only in response to an email from the court, the ruling said.
Any subsequent breaches, regardless of intent, could result in more stringent penalties, including holding Trump in contempt of court and even possibly imprisoning him, it added.