Exactly Carly she still watches her carb intake, so it's managed, not reversed. Once the pancreas stops producing less insulin, diabetes can't be reversed, nor can some of the symptoms such as neuropathy and retinopathy. If your friend were to revert to her previous weight and eat loads of carbs, her blood sugar levels would rise, so she's not "cured". There are some people who are grossly overweight and eat loads of carbs, who are not diabetic and some others who are not overweight who do have T2 diabetes. It's possible to reduce internal fat by losing weight and reduce insulin resistance by exercise and to reduce the need for insulin by reducing carb intake and some other measures, but the pancreas can't be rejuvenated.
I agree with you Greeneyedgirl. "Reversal" is the wrong word. My diabetes is controlled. I'm not overweight, eat low carb, do a moderate amount of exercise and usually have an HbA1c result within the normal range. My blood pressure and cholesterol are fine, but I haven't reversed diabetes. I just manage it really well.
BTW I was one of the earliest guinea pigs for a low calorie restricted diet years before Newcastle Unis started its research and Mosley started making a lot of money from his diets. It didn't work in the long term.