Your position from the first comment is free will and determinism both exist. I have never seen a reason to believe in free will. That is why we are at odds. I don't know if I believe in determinism, but free will as most people use it is incompatible with dialectical materialism.
I stand behind my impression that “both” was intended to mean that diamat is ultimately compatiblist. A claim I disagree with, as I am not a compatiblist, yet I see no conflict between that and my dialectical materialist outlook.