The driver was never charged with a DUI as far as I can tell. There appears to be no legal evidence that he was impaired. He was sentenced to 5 years and released after serving 6 months. He was only charged with leaving the scene of the accident.
Basically, the kid ran out in front of his car. There was nothing he could have done to avoid the kid.
Story after story repeats that he was drunk, but the police apparently had no usable evidence to charge him with a dui.
The story stated that he admitted to having used alcohal and drugs that day. Because he commited a hit and run they woudl have not or little evidence of his impairment so they could not charge him with it.