That's the takeaway for people in charge of the software development, sure. But really, is it even actually a lesson? To my knowledge, there was no accountability, no backlash, no one got fired or reprimanded, no manager was denied a promotion. What lesson was learned by the stewards of the system, really?

Meanwhile, a lesson was very much learned by Mr. Tartaro who, as a DEFCON speaker, should have absolutely known better. He was playing with fire, and now he's suffering the consequences. I don't want to come across as defending the system in use, although it seems to be as much of a social issue as a technical one with people interpreting the text field as being invalid, but this was clearly a dumbass thing to do.