This seems really odd. What would cause DL to deem the situation so drastic to divert the flight, incurring the costs of diverting, and delaying passengers over an issue that the passenger doesn't even end up getting charged for? Granted I wasn't on the flight, but from the article and the outcome it sounds like an abuse of power by the FA and Captain, as well as a waste of the passengers' time.

This story, while a little different, reminds me of the travel blogger who got kicked off the UA flight from EWR-IST flight for taking pics while boarding. Granted he said something stupid, but he was completely harmless.