As the article goes on to explain, the physical evidence for the flood indicates that it was only local. There's also the fact (not specifically mentioned in the article), that the pre and post flood geography of the Edenic region is clearly described in the Bible as being the same - the geography would not have changed as a result of a local flood, but would have been dramatically changed by a global flood. THis is a somewhat confused statement. Using a figure of speech does not mean that you're saying something which isn't true. It does mean that the words are not to be taken literally. To use a venerable example, if I say it is raining cats and dogs that doesn't mean that I am not telling the truth. But it does mean that you're not to take the words literally. The phrase 'raining cats and dogs' means 'raining heavily', and I am certainly telling the truth as long as it is indeed raining heavily.