Their job can be dangerous, and they're only human.
Which is all the more reason to allow citizen recording. When some flaming asshole decides he's going to accuse the police of excessive force, brutality, what have you, third-party record of the incident will be the police officer's best friend.
So, you ask "what kind of project do you need a cheap system and 1080p video for?" Believe me, if I fry the hardware, I'll be glad it's built cheap. I'd rather fry a Pi than an Arduino. That's the whole point of the Raspberry Pi: a system that won't set back an experimenter (or a kid's parents) big money if somebody's voltage calculations were wrong.
As someone below points out, it also makes better sense for schools: for a student taking an electronics course, having parents pay a $35 deposit on an RPi (refunded at the end of the year) makes for a lower entry barrier than a >$150 deposit on (name your other device).
The accuser's lackey hands over information, before the Court decides if it's appropriate to enter it into evidence. The Court decides it isn't (yet) appropriate, and orders all copies of the evidence destroyed.
IOW, the accuser is now accused of making a bunch of copies of something, without permission. They just got a taste of their own medicine, at the hands of an unhappy judge.