What do you do when you detect anomaly? Have an unpalatably expensive recount? That can be expensive enough to use as a reliable weapon. How do you know if the final count is complete? Do you track down every voter? These things sound expensive enough to simply not happen.

Instead one side detects enough anomaly for a court to intervene, and the court considers blunt options or leaving the results as-is. For things like Bush v Gore the court is under enormous pressure to act quickly and perfectly, and they voted along party lines.