It was a victim impact statement, not subject to the rules of evidence. The shooter had already been found guilty, and this was an impact statement from the victim’s sister, to sway how the shooter should be sentenced. The victim’s bill of rights says that victims should be allowed to choose the method in which they make an impact statement, and his sister chose the AI video.

I agree that it shouldn’t be admissible as evidence. But that’s not really what’s being discussed here, because it wasn’t being used as evidence. The shooter was already found guilty.