Death is coded for statistical purposes under an internationally agreed set of 'rules' (which are also used for analysis of disease and injury). The current version is ICD 10 and is available on the web. Diabetes falls into the range E10 - E14 with necessary subdivisions.
The likely problem with getting at the relevant data is that application of the coding to stated causes of death on a certificate in the UK is that consideration of the 'morbid sequence' comes into play. When I was involved in the stats process many years ago it was possible to have 9 or so 'causes' listed in the death certificate and the 'underlying' cause appeared in the main published statistics. These data could be amended if a post mortem was conducted because that data was applied (within the year) to the data abstracted from death certificates. Other tabulations, the 'unpublished tables' were available for those who had a closer interest in the subject and needed more detailed data - in effect the data were cross tabulated by underlying and contributory or other causes. So, I suspect that if you ask the right questions or know where to look there will be some stats available which will give a good indication of the number of deaths where at hypo was involved (or suspected and on the death certificate).
My instinct, and recollection, would suggest that the main causes of death are related to heart disease and cancers in an ageing population. Deaths that involved a hypo I do not recall; nor where diabetes was the underlying cause and if any, the numbers will be very small. If there is a sudden 'unexpected' death then inevitably a post mortem will be carried out. In such circumstances the certifying doc would probably include diabetes related information on the certificate and at post mortem, an wholly independent assessment, this might or might not be confirmed. Data for the sudden death in the young or near young would probably throw up some cases where a hypo was at the least suspected as a contributory cause.
Undoubtedly, many die because of conditions where diabetes was a major contributor. However, that's life as they say and does sit really matter? For those of us of a certain age death becomes a daily inevitability. When asked how I am I normally simply say 'still vertical' - which baffles my French friends. And each day when I awake I am still thankful for being vertical.
Why worry about death from a hypo. It could be a bus, a trip over the cat or................