My sister, and BIL have a young dog. I was talking to my sister about a lady who was keeping her dog in a hot car at the store, and she said that my BIL keeps their dog in the car sometimes, when it's not too hot. My sister said that he leaves water with the dog, and probably cracks the windows. She said that he goes out frequently, and checks on the dog. I'm sure if I brought up my concern, then there would be a big or deal. Would I be an asshole if I just kept my mouth shut? Would it be worth arguing about it?