Earlier quoted context omitted.
Are you reading what you are writing? People can (and do) know things without having enough evidence to stand up in court. It’s how 99% of everything works, frankly. Banks right now are denying transactions because they ‘know’ it’s fraud, based on ML models and probability and no other evidence. If you require someone to not ‘know’ something until they have enough evidence they could prove it in court, they won’t be…
In other words, they don't know. They just have a fuzzy feeling, nothing more than that. Would you be okay with the police being allowed to randomly enter your home and seize whatever stuff they want, just because they have a hunch? Or would you rather they have to get a search warrant first, which requires at least some form of evidence?
You might also want to look up ‘exigent circumstances’ and ‘parallel construction’.