Though he and his fellow trainer Jillian Michaels were initially hesitant to comment on Frederickson's new 105-pound frame as Dolvett Quince was her trainer on the NBC reality series, he opened up about the headline-making transformation during an appearance on The Rachael Ray Show.
In an interview taped on Feb. 6 for an episode set to air on Feb. 13, Harper was asked by Rachael Ray if he thought Frederickson had lost too much weight.
"What people don't understand it, when the contestants leave to go home…they're in charge of themselves," he said. "So I had not seen her until that night,and so when she walked out, I was just kind of like, whoa. And I've been on the show since the beginning."
Harper went on to say that he was "stunned" by Frederickson's appearance, which was clear given his on-camera reaction, along with Michaels' during the episode.
"I was stunned. That would be the word," he admitted. "I mean, we've never had a contestant come in at 105 pounds."
The day after the finale, Harper sounded off on the controversy on his Twitter. "Jillian and I want to take a moment to congratulate all of the BL contestants on their hard work," he wrote at the time. "We're not comfortable commenting on Rachel's journey because we weren't her trainers and weren't given an opportunity to work with her at any point."
Frederickson's trainer Dolvett Quince broke his silence on his contestant's 155-pound weight loss via a Facebook message posted on Wednesday night, saying, "Rachel's health is and always has been my main concern and her journey to good health has not yet ended!!"
At the finale, Frederickson insisted she felt "amazing" during an interview with E! News, saying, "I feel truly alive and just transformed. I couldn't be more happy, more thankful to get this second chance to take charge of my life again."
(E! and NBC are both part of the NBCUniversal family.)