The emotional moment came when Dan, who co-created the series with his dad, Eugene, was discussing the emotional toll series finales can take. While doing so, the 37-year-old actor referenced Garner's former TV show, Alias, which aired its finale in 2006.
"I feel like all of us on this chat know now what it's like to shoot a last episode of a series, and a series that was quite definitive. I lived and breathed for Alias, that's just a sidebar. Hopefully one day I can tell you about my feelings and my love for it and how it shaped my life in 1,000 ways," he told Garner, before more fully explaining his feelings on finales.
"I remember watching the finale of Friends and you're kind of watching these people [whose] whole lives had changed by way of this show. Part of the joy and excitement of watching that last episode is trying to discern, is it the character or is it the actor? The beauty of it is that it's both," he said. "If you can do it properly and if the story's told right, you really get to maximize that sadness and happiness and joy and pride and all of those feelings that come with saying goodbye to something that you love so much. To get to do it ourselves was such a joy."
Dan's mention of the final episode seemed to get Garner thinking about Alias ending, something that made her tear up.
"I can hardly watch last episodes of shows because goodbyes are so hard. I've never seen the final episode of Alias because I say goodbye to Victor [Garber] in it and I can't take it," she said of her co-star. "But your show really did that for me too."
"Oh my gosh, I'm going to have to call him," she added of Garber as she fought back tears.
When Dan moved the conversation along by asking Garner if her final day on set had been emotional, the actress simply nodded because she was too choked up to speak.
"Dan, change the topic!" Annie quipped after noticing Garner's emotional state.
"It's OK. It's a beautiful thing," Garner replied. "They wrapped me and they wanted me to give a speech. The whole stage was packed with anyone who had ever worked on the show. I just couldn't even [do it]."
"So I just hugged every single person there and thanked them. I just remember it was like a mantra. I had to say it 1,000 times to even begin to say it enough," she continued. "Because how do you cap that?... Of course you'll still see each other, but this moment... it dissipates a little. Luckily we're actors. We go on. We have another one."
As for the Schitt's Creek stars' final day on set, Annie recalled filming the goodbye scene with Dan and Catherine, an emotional moment that was the last thing to be filmed for all three actors.
"Those tears are not fake tears. Those are very real tears. I think you can basically see Annie Murphy and Dan Levy. It's not David and Alexis. It's the two of us having a real cry," Annie said. "It was kind of the perfect way to end everything."
Dan agreed with his onscreen sister, before poking fun at her lack of emotion over the final season -- which earned 15 Emmy nominations -- up until that point.
"The whole last season, Annie never cried at a table read, was very stoic. I was always the one being like, 'Really? The last episode table read just not doing it for ya?' OK. When is she gonna break?" he recalled. "And then finally, on that last day, in the rehearsal, Annie completely fell apart. I don't want to say that it made me feel good, but it was a nice thing to know that [she cared]."
"You laughed maniacally! You saw me crying and you were [laughing]," Annie playfully shouted. "You'd just been waiting for it."
"I had the pleasure of moderating a conversation between #EugeneLevy, #CatherineOHara, @instadanjlevy and @annefrances about their groundbreaking show, @schittscreek, a love letter to the silver lining of being stuck in a claustrophobic space with your family (sound familiar? 😬)," Garner captioned the clip. "If you loved #SchittsCreek -- please enjoy. If you haven’t discovered it, yet -- today is your lucky day and I am jealous. And if you cry at series’ finales, well then guess what. So. Do. I."