This is ignoring other words that we have. If Crazy Carl says that something happened, that is a claim, not evidence. That something is missing is evidence, but not that anyone/anything in particular took it.

And pushing that "alleged facts" boil down to "someone says" is ignoring some methods of science. Some people have recorded what the value of gravity on earth is. They have also recorded an analytic equation to calculate it, with the argument that it would work in other locations. They have then worked examples validating the equation in other locations. They have also given directions for how you can, personally, validate the value where you are. This is all very different than "someone says."