That's why we require evidence before we reject someone's claims.
What? We require evidence before we accept claims, not before we reject them.
No, it depends you see, when minorities claim police misconduct, those claims require evidence before we accept them. In the case of a 'former' Neo-Nazi claiming Jewish heritage we accept the claim without evidence.
But this was a claim about someone else. Let's hear from his mother. If I said something about you should the claim be believed until proven false?
This was a person's claim about themselves. If you have no evidence to the contrary, you obviously cannot accuse them of guilty of being dishonest.