Revealing mistake: Throughout season 2 on several occasions it's clear that John Terry (Bob Warner) is wearing a fake mustache and a fake beard.
Factual error: Invoking the 25th amendment cannot be done by vote. The members have to send in their written declaration that the President is unable to discharge the powers and duties of his office, the Vice President shall then immediately assume the powers and duties of the office as Acting President.
Chosen answer: Nobody knew, not even the writers, until at least halfway through the season when they were writing the end. They wanted to keep all options open.
Nick N.