I was not technically diagnosed with Type 2 diabetes, though I probably should have been. In 2008 my blood glucose test on my annual physical was 135, but my doctor didn't seem that concerned with it. My triglycerides were sky high, and my TSH was through the roof too so I was hypothyroid. Last summer after cleaning up my diet, I purchased a blood glucose monitor and used it for a couple of months. It was an exploration of what foods did what to my readings. I was able to get to fasting blood glucose levels in the 80's. From my experience, fat and protein were not the food types that significantly triggered glucose/insulin response.
Have you read the MDA blog on this? Here's the link: Does a High-Fat Diet Cause Type 2 Diabetes? | Mark's Daily Apple It references the study your friend spoke to you about, and what the "flaws" in the science were.