I developed a new algorithm and have exposed my solutions to a company for commercialisation verification. The solutions were well checked and meet all the requirements by industrial standard. No issues had been raised during the verification. Recently the company released similar functionalities in its product. After I raise my concern on the similarities of the new functionalities in their product, the person who was responsible for the verification told others on the email list the solutions he received from me did not work although he kept asking for more solutions later on and no any issues had been raised during the verification. He insisted on that my solutions did not work and he did not undertake "reverse engineering" from the solutions I provided because my solutions did not work properly. I have the emails to prove that he was happy with the solutions and the verification lasted almost a year from simple demonstration projects to more complicated projects and finally by a real large project. I also have solutions sending to the company and they can be checked by third party. Is the comment from the person on my solutions considered as defamation for my algorithm?