I have no reason to think you're lying about the first part (although I'd point there's several ways that metric could be misleading, and approximately every piece of evidence available suggests it doesn't generalize), but the second part is very fishy. There's really no way for you to know whether or not you'd have written the same code or effectively the same code after reviewing existing code, especially when that review must be fairly cursory (because in order to get the speed up you claim, you must be spending much less time reviewing the code than it would have taken to write). Effectively, what you've done is moved the subjectivity from "how much does this speed me up?" to "is the output the same as if I had done it manually?"