It doesn’t and anyone who declares a court found someone innocent is incorrect.
The legal system is subjective, it is a system built on belief and not fact.
I am offering no judgment, just a statement of its condition. Even the precept “innocent until proven guilty” applies to a presumption rather than a fact and the subjective influences of the judges and juries are inherent in the process.
It is a leaky boat that has the purpose of keeping the ship of state from sinking.
Like praying, it works when it works.