Our society, our justice system, and our corporate culture has an enormous bias in favor of harassers, abusers, and rapists. There is enormous pressure to marginalize, ignore, and punish victims, to ignore accusations, and to protect aggressors.
See - practically every single instance of rape/harassment/abuse that has hit the public eye. The consistent pattern in all of them is how many victims had to come forward, how many complaints were filed against HR, how many people had to tell the same fucking story until someone took them seriously.
If you are an actual harasser, the deck is incredibly stacked in your favour. The odds that you'll be punished are low. If you also have actual innocence on your side, and lack of any proof on theirs, the odds are even lower.
There needs to be more justification to this statement. What happens in HR is basically a black box to most people.