Medical shock refers to very low blood pressure which results in poor oxygenation. It's usually fatal if left untreated. (It can be treated with oxygen and IV fluids). I would guess, though, that 'shock' is used in this context to refer to the explosion (as in shock wave).
On the other hand, food poisoning kills many more people than plane accidents. Despite that, I have heard a lot more from the media about fatalities from plane accidents than from food poisoning. And I suppose that's simply because fear sells.
It is suggested in the Hacker News guidelines that one does not editorialize the title of an article. The actual title of this Wikipedia article is "Hong Kong Internet Exchange."