Caplan reveals that the writing staff was actually in the middle of working on what was supposed to be the show's next season when they learned of the news.
"I drove in to work. It was the first day for the writing staff of the next 13 shows," Caplan tells The Hollywood Reporter of how the fateful day started out. "We knew that it was going to be a kind of a bittersweet greeting of the new writers because we had really wonderful talent scheduled to write the next 13 episodes. We also knew that we couldn't start today. We hadn't found out that ABC had canceled the show yet, but we also knew that none of us were in the frame of mind to start writing the show under the circumstances. We got together as a group for the first time and there was a lot of bittersweet hellos -- and a couple hours later, a lot of very difficult goodbyes."
"We found out first through the press," he continues. "We weren't sure if it was accurate. But then we heard from [co-executive producer] Tom Werner that the show was canceled. We all knew it was a possibility but the suddenness of it was a shock."
However, Caplan says the crew stands behind ABC's decision.
"Roseanne's previous behavior had been concerning but we thought it fell under umbrella of politics and the crazy conspiracy theories that she likes to traffic in," he comments. "Some of that we thought was her own private opinions that she was entitled to. But when it came to something like racism, there was no longer any way to accept what she was saying."
"Everybody was still stunned after the cancellation," he adds. "Everybody knew how bad the tweet was and how ugly and ignorant it was. But the suddenness in which it all happened left us all dazed. You're expecting to start a season, everybody has got ideas and is excited about what we can do and work that might not have been seen on television before. And then suddenly it's over."
Previously, Caplan says Barr was "reasonable" to work with when it came to differing political views.
"Roseanne was in the room for the beginning of season 10 and she was quite reasonable with the writers," he recalls. "She knew that a lot of the writers did not share her political beliefs -- although a lot of us had come from firmly middle-class or lower-middle-class backgrounds. She was reasonable to work with at that point. There were suggestions she made that we didn't think were the right direction for the show and she was willing to let those things go. ... I remember there was a kind of give and take that I thought was a workable situation."
"I would be surprised if she returned in any form," he says of Barr. "I think she probably has personal things she needs to deal with. I don't think there's any room for any kind of conservativism on TV that borders on racism. I'm sure that's not what they intend to do on Last Man Standing. I wish them all the best. And I think there is room for all kinds of voices on television -- as long as they're respectful, humane and thoughtful. So if that's what they're going to do with Last Man, then I applaud them for that."
Caplan also says he doesn't know if ABC will compensate the Roseanne crew in some way.
"Everybody is still in shock at how quickly this all went down," he explains. "It's unfortunate because the writers did pass on other jobs to take this job and nobody really knows yet what kind of compensation they're going to get. Everybody is a little bit on edge about how it's going to turn out. But we all know it's a wasted opportunity to write more episodes."
"Don't feel sorry for me, guys!!" the 65-year-old outspoken comedian wrote, also apologizing to Jarrett. "I just want to apologize to the hundreds of people, and wonderful writers (all liberal) and talented actors who lost their jobs on my show due to my stupid tweet."
"Hey guys, don't defend me, it's sweet of you 2 try, but...losing my show is 0 compared 2 being labelled a racist over one tweet-that I regret even more," Barr added in another tweet.
For more on Roseanne's cancellation, watch the video below: