By way of some friendly, non-legal advice feedback, the statement by the school admin person is nonsense. It did make me laugh a bit, so it had some value. A private citizen/corporation/school district/etc. cannot "prosecute" anything. To get a DA, City att'y, Cty att'y - whatever veriety you have there to file a charge against you: 1) there would have to be evidence that you violated a statute or reg. implimenting a statute (i.e., the law) 2) he'd/she'd have to decide that it was worth the time and money. Even if somehow, there was some law you had violated (and - again, has made me laugh a bit just to think about it), the chances of (2) would still be nil.
On the civil suit side, I can't see anything to worry about either - from the school dist or folks appearing in the video; the latter for the same reasons a news crew that might have filed the same sort of event or a riot or a march, etc. is not going to get releases from the folks in the footage.
Good luck.