I was once out at a football field with a track around it throwing some backhand drives. I griplocked one and it went way right.... right towards the parking lot. There were only a few cars there, but of course my disc was headed right at one of them. I think I was running towards the car before my follow through was even done. I didnt see it at the time, but there was someone in the car. He was in the backseat changing clothes to go running and my disc tagged his window hard. He said it scared him so bad that he actually pissed himself a bit. We checked the damage together and there was none, thankfully.
It sucks that someone, obviously a discer hit your window and just took off like that. I hope you find who it was and they pay for your deductible at least. Best of luck to you