Responses
Going for the supernatural route in the middle of the plot when from the very beginning the story has been established in a real life setting, I think it would be a poor-writing choice.
Sure, you can have a supernatural plot, but there needs to be hints from the very beginning.
I guess the foreshadowing for it being supernatural could be there but you have to really DIG very deep, and I think it’s too much of a reach.
This does have a horror tag. Murder could be a part of that, but so could supernatural things like ghosts. The author already has done a similar concept with their previous book. What if does kill him and he comes back to haunt him? Maybe I'm stretching it tho.