First, that the pranksters were so egregiously responsible in the way they went about it. They avoided disrupting any actual educational activities; it was meant to be harmless fun, not vandalism. No harm came to anything here.
Second, that they documented their findings to the administration as part of the action, including recommendations for improvements.
Third, the administration took this as exactly that: a harmless prank by smart, ethical kids who ALSO did them a favor by pointing out the vulnerabilities. If the admin had a panicked fit about this, they could have made it an ugly situation.
My educational experience was populated far more by "freak out and yell" types than this school district, which was a shame.
Assuming you took the video at the top of the article, it was presumably trivial to figure out who was in the class you were in and then rule out everyone who appears on camera as the camera man. Or just ask the teacher...