man, why must you take things out of context?
it's a simple example, take it as it is

does it even matter if he doesnt know?
some guy walks up to someone in the street pulls a gun on someone and shoots them?
does this not make them a bad person? or a killer? or a murderer?
does it not make them such a thing?

and then your friend tells you that he is, and saw it
but you say i didn't see it, its not true