this assumes a bitflip would result in an immediate reboot which is not even that likely i think. detecting these failures probably requires redundant systems and luck i guess.
That might miss bit flips that don't affect the flight profile, but those do not need a real time response. Bit flips in collected data for example could probably be found afterwards when the data is analyzed.
Heck, it might even make sense to figure out what the minimum time, T, is such that something can go wrong that a reboot will fix fast enough to save the mission but only if the reboot happens within T seconds of the onset of the problem. Then just reboot every T seconds regardless of whether you know of something actually wrong.