Registration number N101DN. According to the NTSB, it's a Hughes 269B, and the pilot was Cline Hogg, a rancher from Fontana CA. He was 58 at the time.
He had told the instructor he had 500 hrs experience, but declined to tell him for what type; only one hour in the past 90 days was for a helicopter of this make and model.
The instructor had told him to wait for him, and not to touch anything. The student declined to accept this instruction.