Flying Trampoline does damage

[suev]

We had a trampoline in our backyard that took flight during a wind storm (Jan. '08). We are located in Pennsylvania. The trampoline landed on our neighbor's picnic shelter roof. The trampoline damaged the fence surrounding their pool and also slightly damaged shingles on the picnic shelter roof. Our insurance company (State Farm) said it was an act of God and would not cover the damage. Our neighbor did not want to file the claim with her insurance company. She had an independent contractor who said it would cost $750.00 to fix the damage. We then got our own contractor who gave an estimate of $495.00 to fix. We told her that we would be more than happy to pay the $495.00 to fix the damage. She did not want our contractor. We recently received a letter from her insurance company saying we need to pay them the $750.00. Apparently, they paid her $500.00 - she had a $250.00 deductible. Are we responsible for paying the insurance company? We have never received a call from this insurance company asking questions about the incident, just a subrogation demand. Also, is State Farm correct in saying this was an act of God?