The experiment saw 100 metric tonnes of iron-rich dust dumped into the Pacific in July 2012 in the belief it would feed salmon and capture carbon.
Last month, Russ George launched a civil lawsuit against the Haida Salmon Restoration Corporation and others involved in the project.
He alleged he was wrongly frozen out of the venture and subjected to false, defamatory and malicious accusations by his former partners.
But the corporation has filed a response in B-C Supreme Court, alleging George made false and misleading claims to persuade the company to proceed with the experiment.
The document also says George contributed little and did not have the expertise he claimed and alleges he removed equipment and data from the company's shuttered office.
None of the allegations levied by either George or the corporation have been tested in court.