The sentence is a train wreck to begin with. "Conspiracy theory" isn't a potential cause of death, and these things do not really form a coherent range. Presumably the conspiracy theories allege murder? In that case, I might write something like: "Turing's death is still an openly debated topic, with purported causes of death including simple accident, suicide resulting from bullying by the state, and even murder at the hands of a conspiracy."

Your P is objecting to 'other conspiracy theories' (thus implying the forementioned is one).