haha, as a landlord, I say you have 10% chance..

1. landlord policy does not cover any of tenant's content, I am sure your lease clearly spell out the details on that.

2. you can sue under his liability policy, you may have a small chance, sometimes insurance doesn't want to be in court for such small claim, if they hire an attorney, will cost more than $500, but again, it is up your landlord, if the landlord persist to go to trial(which I would, why not, win or lost, doesn't cost landlord a dime), chance of you winning, maybe slim...