My take on Pence is a bit more aggressive. Comparing his role as VP to how he ruled in Indiana, IE. look into how he dealt with the head of Education there that was elected specifically to counter his slashing of the education funds(he acted like a dictator).
What I see is that Pence believed that Trump would be caught in a myriad of illegal activities and would be evicted from office. Leaving Pence as the President. The thing about these authoritarian figures, is that their arrogance knows no bounds and it diminishes their caution and logic at times.
Thus, I don’t think that Pence believed that the depth of the treason in Trump’s office would be exposed.
Pence gets high level intel and he’s no idiot. That’s actually the most dangerous thing to assume, is that he and Trump don’t know what they are doing. They do, they just underestimated the fervor of the intelligence community, the guts of the press and the intensity of the citizens defense of their country.