Sand/gravel generator is still working

http://www.youtube.com/watch?v=IlAtUDR94RI
The video is telling is everything...

It's a generator machine which only adds 1-tick more in the whole construtction...

Normaly Minecraft Engine and fix report: it shouldn't be possible to creat such a thing.
Mojang, you know what I mean.

Have a look at the video.