I don't believe that the fraud refers to the "getting past security" part. The fraud that is being referred to, and the resultant injury, is to the airline as it prevents them from selling the same ticket to someone that does intend to use it.
I must add, however, that all the talk about the airline being able to sell it to someone else is, IMHO, irrelevant. The airline doesn't care where the $$$ comes from, after all, a dollar is a dollar and if they are selling a ticket that is fully refundable, then they must have an expectation that a percentage of those tickets will be refunded. Whether or not malicious intent could be proven remains to be seen. I suspect, however, that the publicity surrounding an airline that chooses to pursue a criminal complaint would not be good publicity and the airline would be hesitant to push the issue.