Innocent until proven guilty is a criminal philosophy in the US court system.
Companies, and social media operate at the social level. Reputation and impressions matter. Companies are not bound by the same rules of conduct that courts are.
It's unfortunate that the internet likes to have a character to hate, and fully engages in the hate machine when somebody is served up. Sometimes the target of the 3 minutes hate is innocent, and they just suffer even if their name is cleared. The damage is done.