Radon is a lot of hype. The only people who get lung cancer from radon are either smokers, genetically predisposed, or live their entire lives in a basement with 200 pCi/L. I'm half joking, but seriously, I have a lot of education and experience in radon and have attended EPA conferences in DC. I got the feeling there were a lot of people there protecting their jobs.
If I had a home with an unfinished basement with 10pCi/L and the livable levels at half that, I wouldn't worry about it. The EPA limit of 4pCi/L is VERY conservative. You breathe in more carcinogens by sitting in traffic.
As for the granite, there is insuffucient data there to make a conclusion. That granite could have a number of radioactive materials with varying degrees of ionization. It's the same reason you shouldn't test for radon near a smoke detector... they contain Americium (radioactive) and will skew the results.
And the "radon technicians"... In most states, it doesn't take much to get "certified". 46 States have no education requirement. Most of those "technicians" have no science background.
It takes approximately 20 years to develop lung cancer from exposure to moderate levels of carcinogens. I'm pretty sure that woman with the granite wouldn't be in the hospital the next day getting chemo if she didn't have them take it out right away.