Scumhunting only works if you know the person already. You can't reach conclusions without data.

I tab out during the night and wait for the gong. Even if I'm a PR, I tab out after I vote. The only exception is when I have people to chat with, since it's rude to ignore chat. This critically means that yes, if I am cop I will be tabbed out when the day starts. It only takes me three seconds to get back into the game. This means my cop reports are sometimes a few seconds late. This wouldn't be a problem if idiots didn't think that a faster typist is more trustworthy. Every halfway competent maf figures out their fake report and a backup before hammering, and can spit out reports or even bubble guilties just as fast as the real cop.

Also: Fun with fractions! In a 'nilla (or fancy pants) setup, the real cop has 1/6 odds of guiltying his cc and, if he's a slower typist, his report will be posted second. He also has 1/6 odds of guiltying the corpse. This means that if you assume any cop who guilties his cc or a corpse is scum, you will lose on D2 fully one third of the time.

More fun with fractions! When you have a mislynch, count the total number of towns and the total number of mafia. If the mafia and towns are both even, always, ALWAYS wait a night before using the ML. Let's take the simplest examples of 6 town/2 mafia. In a 6 town/2 mafia, you have 1 ML and a 2/8 chance of hitting a mafia. If you wait a night and mafia kills someone, you have a 5 town/2 mafia and a 2/7 chance of hitting the mafia, and you still have exactly one mislynch. Better yet, if your cop is still alive he will have more reports. Even if he's cc'd, so long as you lynch the fake cop you can go back and reread and you'll know that all of the real cop's reports are real, including the one he can now produce on the night of 6 town/2 mafia because you didn't lynch that night. Remember to consider whether roles like Fool or Killer might give the mafia an extra member on the last day when crunching these numbers - in some setups, the number of town-sided players vs. the number of mafia-sided players is not always clear.