There are only 2 possibilities 1) The patient took the a cholesterol lowering drug & then discontinued it or 2) There may be an error in the laboratory reports . Unless the drugs taken by the patient are available , it is difficult to comment further .
In my opinion, it's possible (1) the patient didn't adhere to specified nutrition regimen (2) there may be possible drug-drug or drug-nutrient interactions that could have led to inhibition of the drug's effect.