I PHONE 13 SIDE BODY NEAR POWER BUTTON PRESS INSIDE A LITTLE

while i was sleeping in bus i kept my iphone 13 in my pant pocket. when the bus jumping due to bad road. my phone touch the bus seat rod. Due to this body of my iPhone 13 is slightly damage and paint of that side gone. Apple advertisement showing that nothing will happen to the I phone when fell down. Then what happened to my phone when it fell down. My i phone not touch the bus rod directly, it was in my pant pocket. then how it damaged