"Such sad news & I'm so sorry to hear this. I do remember this photo and his interview. Sending love & thoughts to all of Jonty's friends and family especially his Mother Sue. Kia Kaha," Carter wrote on Facebook and shared a photo of the two of them.
Carter, who moved to France at the end of last year to play for French club Racing 92, promptly responded to a post from close friend Kate Hartley who asked for his support and if he could share the photo of him with the teenager on his public Facebook page, which has 982,950 likes.
"He had a huge passion for rugby. Jonty looked up to you and wanted to be an All Black just like you," she wrote to Carter.
Jonty's mother Sue Carran, who accompanied Jonty to the press conference, said the Year 9 student would have been blown away to know the first-five had remembered him. "If Jonty knew that he actually remembered him it would probably start his heart up again."
His mum and dad, Graeme, were still coming to terms with the sudden death of their eldest son. "He was a 13-year-old boy and he just went to sleep one night -- this was on Saturday -- and he never woke up. For some unknown reason his heart stopped. He had a big heart, he had just had a full day at athletics. In our eyes he was very talented and a hero and he just didn't wake up," Mrs Carran said.
He leaves behind two younger siblings, Charlie, 12, and Libby, 10, who would remember him as a caring, fun-loving boy with a passion for sport.
"He was so caring. He cared about people young to old. He was a great teacher. He would teach kids how to ride a motorbike, how to high jump, how to do anything," Mrs Carran said.
Jonty was a Year 9 student and had just started boarding at Southland Boys where he was thriving with all the sports opportunities. He did athletics, played rugby and golf and had a number of trophies and medals recognising his achievements. He won his last trophy on Saturday -- the day he died -- for the most individual points at the Otautau Athletics Club.
"He was living the dream. He had a huge respect for people. It's so sad we just bought his rugby boots on Saturday and he will never get to put on the Boys' High shirt."
The family had been touched by Carter's message which paid a special mention to Mrs Carran, as well as the overwhelming support from their local community and strangers further afield.
Jonty's friend, Kate Hartley, posted a message on Carter's Facebook page saying he was a big fan with a passion for sports and asking him to show support to the Carran family and share the photo of him and Jonty on his page to which he promptly responded.