In an interview airing Monday on CBC News Network's Power & Politics, Devlin explained how he got past the prime minister's RCMP security detail and onto the stage where Harper was getting ready to do a question and answer session with the Vancouver Board of Trade.
"I just wore my black dress shirt, my black pants, and I had a black apron on," Devlin told P&P host Evan Solomon.
Devlin and Shireen Soofi, the second protester, managed to evade security by passing themselves off as wait staff at the hotel where the event was being held.
They did so with the help of Brigitte DePape, who was fired as a Senate page after walking onto the Senate floor carrying a "Stop Harper!" sign during a speech from the throne in 2011 to protest Harper's policies.
DePape, who helped organize today's protest, told Solomon she was proud of what Devlin and Soofi were able to pull off.
"I'm extremely inspired by what Sean and Shireen did. These amazing young people who took this bold action and wore the necessary garb to get into the hotel in order to protest Harper being here because of the Conservatives' complete inaction on climate change.
"Hundreds of thousands of people are dying and being displaced because of climate change," DePape said.
Not there to 'hurt' PM
After getting onto the stage with Harper, Devlin manage to stand behind the prime minister holding a sign that read "Climate Justice Now."
Asked if he was surprised to have been able to get as close as he did to the prime minister, Devlin said "no."
"That was the plan, to get as close as possible."
"What I found surprising is that people are so shocked that a citizen can access one of their leaders when that room is full, I'm assuming of extremely wealthy people, who are essentially paying for the privilege of asking him questions.
"He really goes to great lengths to hide himself, not just from the public but also from the media."
Devlin said he wasn't a security threat.
"I wasn't there to hurt the prime minister today. I was there to communicate a message about people who I believe his policies are hurting."
Security did not see it that way. Devlin was immediately yanked off stage.
The comedian by trade, joked he received a harsh reception.
"I have had a few harsh receptions on stage, but I think that was the harshest," he said.
"They threw me right off stage, down some stairs and then threw me into the kitchen and held me on the ground. I was arrested and released. There haven't been any charges," Devlin said.
He said his back hurt "a bit" as a result of the way he was handled by security.
More protests coming
Devlin said he would go to "great lengths" to get his message heard.
"If we have to put on an apron to get our message heard, and get those voices heard, that's what we're going to do."
DePape said Canadians can expect to see more of these types of protests.
"We won't stop until the Conservative government is out of power, we won't stop until the Enbridge pipeline is stopped, and we will continue to find creative ways to make our message heard."
Soofi, the second protester, got onstage at the same time as Devlin. She held up a sign reading "The Conservatives Take Climate Change Seriously," with the sentence crossed out.
She stood between Harper and Iain Black, the president of the Vancouver Board of Trade.
Security immediately grabbed her by the arm and escorted her off stage and out of the room.
Black, who had just finished introducing Harper when the activists got onstage, said, "I'd like to take a minute and have some folks removed from the stage."
Harper took a sip of water before joking, "It wouldn't be B.C. without it."
The RCMP said they are reviewing the incident and would take "appropriate action."
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