Lightning cable melted and damaged bedding during the night

Does anyone know how to independently verify the damage caused by an Apple lightning cable? I’m concerned about returning the damaged cable to Apple as I might loose the evidence in this whole process. The Apple lightning cable end was separated overnight from the iPhone, but still plugged into the socket at the USB end. I woke up in the middle of the night sensing a burning smell and was shocked to see the lightning end completed melted and burning holes between my pillow and bedding. Usually I charge my phone over night by my bedside, where I sleep by my pillow. Not sure how the cable ended up disconnected and under the pillow. Must have been a disturbed sleep. Still not expecting this to happen. The legitimate Apple cable with s/n was provided by Apple when I bought my iPhone 7+. I kept the lightning cable and used it to charge my new iPhone 12 Pro. I keep my other usb-c cable by my desk to charge my new phone during the day.