What is the purpose?

What is the purpose?

"Proof" and "evidence" are two separate concepts. In particular, remember that for lawyers, "evidence" is often given in court or as part of a deposition: "nah, mate, I was never near the place 'e was killed".

Much of the business of a court is deciding which evidence to accept.

Somebody submitting something like a sworn statement or affidavit stating that they are not employed by a particular company would be considered evidence that they are not employed by that company. Further evidence of their financial affairs (for example, who does employ them) would make that evidence stronger.