FMLA Certification incomplete

I am a union rep .My question is for an employee of the company. He went out on FMLA and the company gave him FMLA paper work. He gave it to his doctor. The doctor completed the paper work and returned it to the company. The company rejected it stating it was incomplete. The company gave him the same paper work back and he again gave it back to his doctor. The doctor sent it back to the company but the company rejected it stating that again it was incomplete. The company, the employee involved and a union rep. sat down to discuss the matter. The company told the employee they were going to give him new paper work and that he had 5 days to complete and return the paperwork The employee gave the new paperwork to his doctor a few days later. The paper work was not returned in 5 days. The company gave him 2 weeks off without pay. The doctor returned the paper work in 15 days and the company accepted the paperwork that covered the days he missed but he was still given the time off. The company said they had the right to do this under section # 825.305 (D) " The employer shall advise an employee whenever the employer finds a certification incomplete, and provide the employee a reasonable opportunity to cure any such deficiency." Thank you in advance for any help you can provide on this matter.