Happened to me on an Engineering Design project I had. My boy from my football team changed the name and a few phrases and it called it his. Instead of making a big ordeal. I simply took my lap top to my professor and should him the date it was originally created, and I also should him the email we had sent between each other. He called my boy into the office and asked to see the documents original date created. It all lined up with the emails. The professor actually gave me an "A" for the paper and also a pat on the back for not going crazy and making a big ordeal about it. My boy..the professor simply had him do it over again and he got like a "B", he explained that football was kicking his butt and he didnt have time and he admitted he was wrong. Try it man, the computer and email dont lie.