The court logic fails on one basic point - you didn't use the courts. You cannot expect to gain the benefits of court procedure without also taking the work or detriments involved.
There are many logics you could apply here:
For example - did you get the 25,000 GP for that shield all by yourself, or was it bought with shares of party treasure? If the latter, there's the argument that it, and all items ever acquired using party treasure are all really party property. You were chosen to manage some share of the treasure, and you bought the shield. It's gone now. It is not your loss, but the party's. What to do about that is still a party decision, not yours alone.
For another example - if instead everyone considers it to be your own item, you still may not have much ground to stand on. If you were alone, and the item were stolen or broken, and you needed help recovering it from the criminal who took it, would anyone risk life and limb to help you for free? No. You'd have to pay them. Much the same here - the party all took risk, all put forth effort. You don't get to recoup your personal losses using their effort for free.
The partys I like to play with are all usually team-oriented. We'd replace major items off the top of the treasure pile, and split up the rest. On the other hand, nobody in the party would demand that of his fellows. They might ask, politely. But that isn't what you did, and that might be part of your problem, now.