A New York real estate investor sued Herrick Feinstein on Wednesday over claims that the firm missed key deadlines in his case against a business partner, seeking upwards of $1 billion in damages for alleged legal malpractice.

Jacob Frydman and companies United Realty Advisors and Prime United Holdings claimed Herrick bungled discovery in their federal racketeering lawsuit against Eli Verschleiser and others. Frydman said a report by a computer hacking expert and another expert’s $380 million damages estimate can’t be used at an upcoming trial because Herrick served them a month late.

“Herrick charged plaintiffs more than $100,000 … to assist in the preparation of the reports, in unsuccessfully opposing defendants’ motion to strike those experts’ reports and their testimony, and in objecting to [the] preclusion order,” the new suit says. “All of these legal fees were rendered useless as a result of Herrick’s malpractice in missing the court-ordered December 16, 2016 deadline.”