most obvious things are often enough the mostly wrong ones - this is why everyone was sure for centuries that the Earth is flat or that the Sun and stars are orbiting the Earth. and this is why people invented specific protocols to ensure (or at least come close to) correctness of theories. these are called proofs.

and, for example - if you are using one specific LEGAL definition of a genocide then you have to prove LEGALLY, following the regular process. if you're not doing it, then it's per definition not a proof.