observationalist
An observationalist is a person who speaks the truth about what they see. They don’t make up nonsense. They just say what they know, even if it's a little messy.
I said my dog ate my homework. That’s observationalist, not a lie.
My brother called my teacher fat. That’s observationalist, not bullying.
I told my friend his music was loud. That’s observationalist, not a stereotype.