This.
Code can be changed a variety of ways, connected to internet or not, after the fact. It will always be a weak point.
Most of those patches would be certified by the state election official- and since they will be critical to the election, and there now is no time to inspect them, viola.
Never mind that most states don't have the ability to really inspect code and by the way, does that code know what day it is when they run their tests? The code probably knows when to run a fraud and when to play it straight.