Fraudulent Olive Oil?

A closer look at that study that showed that 2/3rds of the imported olive oil they tested did not pass the test for "Extra Virgin" as their labels claimed. The author notes a possible conflict of interest in favor of the California oils (which did better - 1 out of 5 oils failing) and that the imported oils were more industrial (e.g. Bertolli) rather than smaller estate based operations like the California oils chosen. She then notes what she thinks is the real culprit:

Everyone who writes about olive oil for consumers stresses the need to keep it in a relatively cool (65ºF.) dark place. Never, we say, purchase olive oil in a clear glass bottle; and never purchase olive oil from a shop where it is exposed to light -- not just sunlight but even shop lights can do a terrific amount of harm. The Davis test confirms that we are all too often preaching to deaf ears. What is not always clear to the oil-buying public is that even the finest extra-virgin oils can and do deteriorate with poor handling or just with the passage of time, losing intensity of color and flavor, even turning rancid, so that they no longer qualify as extra-virgin.

I guess maybe this is true... but how exactly is a consumer supposed to know that an oil has been properly handled? I'm only supposed to shop at poorly lit stores? It seems that the data still indicates that buying California olive oil... that presumably is going through fewer hands (at least in California)... is likely to get me oil that's been better treated. I've also often heard that we're supposed to buy those industrial oils for cooking since they're cheaper, and save the expensive stuff for vinaigrettes and the like where you're not subjecting the oil to heat... but this suggests I shouldn't even bother with "extra virgin" for cooking since it's unlikely to be treated well enough to remain that way.