Let's circle back around here.
The point I was originally making is that "there is no fraud" is the default assumption, which I expanded to default legal assumption. You said that, no, the default legal assumption is nothing. Fair. You also assert that technically, every single US election is in this "nothing can be concluded zone."
Functionally, what happens when you can't substantiate "there was fraud" is that, by common consensus, "there is no fraud" is assumed to be true. And every single US election has, by common consensus, come to be seen as not having fraud when none was proven to be there. So for all intents and purposes, the assumption -is- by common consensus that there was no fraud.
I call it semantic because in a legal sense, sure, it's all, like, nothing. In practical life and use, it may as well be that "there is no fraud" is the default assumption.