In February, the manager of Lidl's supplier SEB-Cerf, Guy Lamorlette, 78, was sentenced by a court in the northern town of Douai on appeal to three years in prison, one of which was suspended, for the poisoning. He was also fined 50,000 euros ($55,000).
The appeals court confirmed a sentence first given to Lamorlette in June 2017 on charges of causing "involuntary injuries due to a deliberate breach of safety operations".
At the time, Nolan's mother, Priscilla Vivier, had said she was content with the verdict, saying "even though it will not make my son come back as before... he can no longer be involved with beef."
The quality manager at SEB-Cerf, Laurent Appere, was tried on the same charges and appeared in the early stages of the proceedings. But he then died of a heart attack. His family vehemently denied claims of a suicide.
Lamorlette's lawyer has said he was considering appealing the prison term with France's Court of Cassation, but Rault urged him to abandon this idea after Nolan's death.
"Nolan's parents hope that one day they will have the right to decency and compassion," Rault said, adding the family was heavily in debt after paying for his medical needs and that Lamorlette had not paid damages.