How many reports were there? Showing me that 26 are likely false doesn't mean much if there were over 100 to begin with whereas if there are 30 then it's likely that there's no problem with the phone. Numbers are only useful when taken in context.
These are independent things. There are phones that start burning. And there are phone owners who are lying (or not even phone owners, you don't need to own a phone to make a false claim). I think the statement isn't "there are much less burning phones then you'd think", but "there is a huge number of liars". Which surely doesn't come as a surprise to anyone.