Angus Mitchell, the only child of hair icon Paul Mitchell, died in a pool at his Honolulu home back in January and little was known about his tragic end until now. A newly revealed medical examiner report stated that Angus died from an accidental drowning, RadarOnline.com has learned. He was only 53. Surveillance video was captured leading up to his sudden and shocking passing, showing Angus in the backyard getting into the water and never reemerging. There was no mention of toxicology in the report, but TMZ noted that much of the paperwork was heavily redacted. A police report stated that wit…