Where did he come from?

And at what point, if any, did our hero realize that something was (horribly) wrong? From the Houston Chronicle:

A driver who hit a pedestrian along Interstate 45 in southeast Houston early this morning didn’t stop even though the victim smashed through his windshield and landed in the front passenger seat, officials said. 

The driver, identified as 45-year-old James John Onak, was charged with  felony accident involving injury in the 177th State District Court, according to a Houston Police Department news release.  

The collision occurred in the 12200 block of the southbound Gulf Freeway near Fuqua about 12:30 a.m. Tuesday, according to the Houston Police Department.
Police said the 32-year-old victim, whose name has not been released, died at the scene.
No other injuries were reported. 

Police said a man was driving his Ford Explorer on the freeway when it broke down. He pulled to the shoulder and got out and began trying to cross the freeway. 

The man was hit by a black Mazda, driven by Onak, police said. Police said the collision forced the victim’s body through the windshield, and he landed in the front passenger seat inside the car. 

Onak did not stop after the collision, police said. Police said he allegedly got off the freeway and drove a few blocks before a Precinct 8 Harris County Constable pulled him over at 11600 Kirkvalley near Beamer, and the deputy noticed the car’s front was damaged. Then the deputy saw the victim in the car, police added. 

Police said Onak told the deputy he had hit something on the freeway and that he didn’t know the victim was in the passenger seat beside him. 

Onak was believed to be under the influence and a mandatory blood draw was taken. 

I'm thinking the sound of a body crashing through the windshield and landing in the passenger seat would be enough to alert anyone that there was a problem.

Sadly enough, this isn't the first pedestrian through a windshield story I've come across.

I have no idea whether Mr. Onak was intoxicated or not that evening. I'm fairly certain that had he remained at the scene the endgame of this said incident would be a bit more favorable to him. As a result of his not remaining at the scene, Mr. Ornak is facing a felony charge of an accident involving death.

Depending on the circumstances surrounding the accident, Mr. Ornak might actually stand a better chance to defend himself against a charge of intoxication manslaughter as the state must prove that the accident was caused by his being intoxicated. Having a pedestrian attempting to cross the freeway in the middle of the night is not a circumstance that any driver can reasonably anticipate facing while driving.

How much warning did Mr. Onak have that someone was trying to run across the freeway? What kind of clothing was the pedestrian wearing at the time? Under those conditions, would an ordinary driver with an alcohol concentration of less than .08 (or who had the full use of their mental and physical faculties) have been able to avoid the accident?

Unfortunately for Mr. Onak, by driving on he has handed the prosecution a gun and a golden bullet with his name on it. The state doesn't have to prove that the accident was avoidable. All they have to prove is that he was involved in an accident in which a man was killed and he didn't remain or return to the scene.

Information - Onak