I thought the same thing. Then it occured to me. Why did they assume he was DEAD? Sounds like they spent a fair bit of time doing nothing. The guy WAS obviously face up. He could have been dying but not yet dead. He could have just had a major head wound. Or a diabetic in shock. Or a stroke victim. Minutes count here people.
So I am going with emergency response fail here. Heck, even the bystanders that called it in for that matter.