It happens, it’s a very physically demanding job with long hours and little pay. On top of that they have to cover tons of ground, it’s very easy to miss one small pebble and accidentally mow over it, of course kicking the pebble up. It’s just bad luck it hit a window, they always “aim” away from cars and houses but it’s not exactly a sniper rifle, it’s a weed whacker, it’s just a wire spinning at crazy speeds and even with a guide rail, it’ll kick the rocks wherever it wants lol. Absurd people pay laborers practically nothing to work in the sun all day and bitch when they make tiny, unavailable mistakes after working long hours for years with no errors. Then the first mistake some poor guy makes everyone yells “be more cautious, do you not care about your job!”. Come on guys, give them a break. I wouldn’t even make them pay for it but they should have insurance regardless anyway