Sadly, just getting arrested and convicted for lying doesn’t remove him from Congress:
They shall in all Cases, except Treason, Felony and Breach of the Peace, be privileged from Arrest during their Attendance at the Session of their respective Houses, and in going to and returning from the same;
I’m pretty sure the GOP would rather have him appear in manacles and an orange jump suit every day Congress is in session for the rest of Santos’ term than risk giving up a seat.
“Are you allowed nowadays to disclose your pivotal role in The Manhattan Project?”
“Would you offer any views as to your Chancellorship of Germany for the past twenty years, and how we would now guide Europe through these difficult times?”
Yes, you might catch him out in a little fib here or there.
That section refers to an archaic legal practice of civil arrest, not criminal. Congresscritters aren’t magically immune from the law while they commute.
Though you are correct that criminal charges, prosecution, and conviction aren’t enough to remove a sitting representative. There are limited mechanisms for that. The primary mechanism that could cause his removal is if he was never eligible to begin with. For example, if he isn’t a legal citizen of the US…