I don't understand why he would have done this. Surely travelling at 60 mph would be obvious on his GPS? Even Guinness would want to understand why he is doing miles in a minute.
What you are saying ties up, but surely he couldn't hope to get away with this? I understand him being in the back of a vehicle and it going at 7 mph (it sounds ridiculous), he could hope to get away with that.
Data can be doctored after the entire run.