I don't think the necropsy being unavailable for public inspection necessarily means anything one way or the other.
After the Exxon Valdez debacle occurred, a prominent newscaster asked the captain why he wouldn't just come out and say he had not been drinking. If he had nothing to hide then the premise was he should just come out and say so. The captain said that for legal reasons (ongoing court case) he had been advised not to discuss certain subjects. Does that mean he was definitely drinking because he wouldn't say otherwise? No.