Was cutting last Thursday at an account I've had since I started (only 2 years). Did all as usual, and went about my route. Thursday evening I got a call from the homeowner. Apparently there was a hole in the outside HVAC unit. I went and looked at it and sure enough there was hole, from a rock or something. Never even knew it happened, never will know for sure I caused it or not. Anyway, they got a cost to repair of $600. I used to do some HVAC work on the side and knew to weld/solder up the condenser, evacuate, and recharge was high. Called a good friend that does HVAC work and he said $300-400. I told the customer that if I was gonna pay, I'd choose the contractor. He agreed. In the end they ended up going with a new HVAC unit as their current unit was 16 years old. My cost is gonna be $350 (cost to repair original problem). This of course will be out of pocket as insurance deductible is $1000. Cost of owning and operating a business I guess. Anyway, I'm always extremely careful at every yard, but extra at this one. They have a gravel driveway that meets their yard and always close my Qwik-chute. Crap happens though.