Anyone else doesn't have to use that. If someone who's called a rapist sues for defamation the courts will use "balance of probability".

People get confused by the apparent contradiction between "innocent until proved guilty" and the fact that someone not prosecuted (or even prosecuted and found not guilty) may have done the crime.

For an example see the comments about football player Ched Evans being found "innocent" - he wasn't, at all. He was found "not guilty" which spans the range from "he definitely didn't do it" right up to "he almost certainly did it, but the prosecution didn't persuade me beyond all reasonable doubt".

So if you're Microsoft you can do what you like. If it ends up in court it's probably going to be "balance of probabilities".