Uhhh, isn't this a lot like any other school-issued property that a kid's family is responsible for when he/she takes it off-campus? After all, school district taxpayers essentially bought the iPads in the first place. Lose the textbook or destroy it, you pay for it. Lose the school-issued football helmet, pay for it. I remember when my sister was issued an expensive IBM Selectric typewriter (we went to HS in the early 80s) and she broke it at home. Totally nonfunctional after that. Our school sent Mom a bill for replacement but later decided to cut her a 50% break on that, realizing that was partially their fault. The lesson for them: keep the expensive stuff on-campus. After that, no more typewriters were loaned out.
iPads have their place in school and ARE the wave right now, being excellent teaching tools if implemented correctly. Until their prices drop to a couple hundred dollars or less, I would recommend any school district to keep them in-class/on-campus only, where caution and control of use can be better effected.
Anyway, good luck in your case. To be honest, I doubt the magistrate will find in your favour. But I could be surprised.
Michael "Spam, spam, bacon, eggs and spam. Hold the bacon and eggs." Sent from my iPad 2 using iPF