Right. It there is any kind of modification to the code that runs on the machine including firmware and hardware levels it would be detectable. If it is hacked without a restart and the hacki only exists in memory then there is no evidence after it is powered off.

This is how a lot of the recent botnets have been run. The ones that have unleashed massive scale attacks on the internet form insecure IOT devices.

Additionally if you consider the stakes involved and the capabilities of state sponsored agencies then you have to do side a deeper level. Even the integrated circuits on the motherboards could be tampered with. The ones that don't even run code can be altered so that they can change conditions presented to the software. This could result in a triggering event in the code which could activate an "unknown programming error" in the code that changes the outcome.

That's why the machines should all be open source on open hardware. Made in the USA and have full certification and code review of the highest standards. The integrity of this democracy deserves nothing less.