I highly doubt this is true. The experiment seems rather stupid: check people using phones vs people not using them for 13 months and see the difference? What kind of scientist does that? It makes much more sense to directly test the effect of whatever radiation a cell-phone emits in sperm cells. Not to mention that cellphones, when not in use, are no much more than a glorified antenna with which you can play games in the toilet. Why would the cellphone be emitting anything when not in a call (it says in the article its constantly searching for a connection, but does that involve any emitting as opposed to 'hearing')? Is that type of radiation even dangerous enough to denaturalize the DNA in sperm cells? If it is, why isn't it dangerous to other, more readily exposed cells like skin cells?
I call it a bluff.