Its complicated, because he did stop it. He also immediately took notes and immediately told others about the conversations, actions which clearly paint him as somebody fully versed in the processes of establishing cooperation with law enforcement on an informer basis.
It is also arguable that the entire insurrection that day was a cover to specifically murder Mike Pence on the Capitol steps. There was day of chatter that the gallow was brought into the city in one of the vehicles in Alex Jones’ caravan. We know that with the charging of Donald Trump, Alex Jones is now essentially the only conspirator of Jan. 6 who remains charge free.
Whatever we think of Mike Pence, our country still existing might have solely rested in his hands and it appears he did the right thing in the way he knew how. He saved his life. He saved his family’s life. He saved his country.