If you look at the link, you will see he didn't write the article. It is simply posted on his website from a site that keeps track of problems with all kinds of meds: over-the-counter, prescription brand names, generics, etc. But yes, Dr. Oz is an MD (heart surgeon I believe by specialty) who has a TV show here in the states.

The article explains how generics are made, how they can vary from the brand name, how they don't undergo the same testing as the brand names because they are allowed to rely on the testing originally done by the brand name manufacturer, etc. It also goes into the types of generic meds that are most "touchy" as far as how the slight changes in the generics can affect the effectiveness of the meds, particularly with extended released meds, etc. Quite interesting actually.