I had to track down the original story for this, but here's the link to it:

http://www.sinchew.com.my/node/102525?tid=2

It's in Chinese, so I can't read it without help of the Google Translator. This is a google-translated excerpt (with my own grammatical fixes) of the news article:

> Xiaogang felt pain after the accident, and immediately called to tell his
> father about his injury. Emergency personnel said they rushed to the
> scene. When they arrived, Xiaogang could still speak, and he was immediately rushed to hospital
> for treatment, where he eventually died of excessive bleeding.
> 
> It is reported that in just one month the Jiaozhou Central Hospital
> admitted three other patients suffering from similar pneumatic rotary chair explosions.
> Although their injuries were also to the buttocks, no objects became
> lodged in the body, and they only suffered minor injuries.

Here is [another news report][1] of a woman whose chair also exploded (with video!). Looking at the images of the chair, it seems to be an identical chair to the one in the first story.

So **yes**, these chairs' pneumatic mechanism can explode, and **yes** it's possible to die from it. **No**, there are no significant statistics available, particularly for outside of China.


  [1]: http://www.liveleak.com/view?i=a57_1345650369&comments=1