Cool. Her thumbnail is pretty clearly a Black womxn, if you're unsure or visually impaired then a good rule of thumb is simply not to tell ANYONE they have a black soul-- particularly in response to something as nonsensical as a TV show, and yes even if it was "just a joke." Other things you could say that wouldn't hinge on potential racism if the writer is a Black person could be "wow I think this is crap! I disagree!" or "you must be joking, this is the best show ever!!!" or just good old fashioned "What didn't you like about it? I'm curious because I really loved it." <-- hint, that last one is a great place to start. Incidentally, it's possible to be funny without possibly being mean and/or racist!
You note neutral things as being black, such as a TV being turned off or a light going out. This is a gross misuse and/or misunderstanding of words and the power that they possess; can you not understand how the invocation of a black soul in relation to her not liking the show that you're enamored with was clearly holding a negative connotation? There is a stark difference between language employed neutrally (as the color black conveying a TV that is off or the color of a Black person's skin) and that which is deliberately employed with a negative or even sinister connotation. It's this kind of "color-blindness" as it pertains to how Blackness is discussed in the milieu of general (particularly non-Black) culture/media/conversation that perpetuates racism in the most insidious way. The lesson here is that it's good to be conscientious of when you are doing the Disney effect of using language or tropes to conflate "black" with "bad" and be extra wary of when you're doing that towards or against a person who actually is Black. And if you don't know, then just avoid it! It's a trope that we could stand to move beyond as a society. Incidentally, even in Eastern traditions that are deeply mired in exploration of light and darkness, "dark" is not an inherently bad thing, contrary to the Disneyification of our collective consciousness that permeates anti-Blackness from the moment we can understand language and/or symbols.
Furthermore, how was this person speaking for the author? Any non-Black person committed to anti-racism has an accountability to call out problematic, racist behavior when they see it. Now, if he had said "Hey! You hurt the author's feelings! You made her feel the pain of racism!" that would be speaking on behalf of her. Noting that you were irresponsibly employing language in a way that could cause harm is hardly speaking for anyone or doing anything other than the civic obligation that every person has in order to root out bigotry in our society.
Furthermore, it doesn't matter if you're not white. If you're not Black (or even if you were, which you're not), you don't have a right to profess that anti-Black racism doesn't exist or you're not capable of perpetuating it because you're not white.
