Cause of death statistics are notoriously unreliable, for several reasons. Most notably, most of the information comes from death certificates, which only have space for a single cause. Often, there are a number of factors which together resulted in the death, and it’s rather random which cause is chosen, and which manifestation of it: proximate, ultimate, or something in between.
You might think that an autopsies would help, but comparatively few of them are performed, and in any case they might not produce accurate results: around one in four are of miserable quality, apparently. Autopsies are done the old fashioned way, with scalpels, but it appears that using scanning technology might be quicker, cheaper, and possibly as accurate.