That sudoku looks hard as ****. I can barely even work it out!
Looks like a beer oyster:
http://tywkiwdbi.blogspot.com.au/2012/01/b...-explained.html
the rate of dodgy product will be more like 0.01% .. or even better.I guess there will always be that 1% or so
Never seen it though, shows even the "big boys" can stuff it up from time to time