Inflicing self-injury

I've read this a couple of times, but I still don't get what happened.

Witnesses told authorities the man was seen arguing with a 24-year-old man just before 3 p.m. at a Citgo gas station in the 11800 block of Starcrest Drive on the North Side.

The two drove to the corner of Jones Maltsberger Drive and Burning Trail Street, but police did not describe their progress there as a chase. At the intersection, witnesses said they saw the younger man get out of his Dodge Ram pickup and start waving his hands to warn drivers behind him to back away, said Police Chief William McManus.

Police said the man in the other vehicle, a Nissan pickup, had stopped in front of the Dodge.

He fired a shot at the Dodge's windshield while sitting in his Nissan and then somehow turned the gun on himself and fired again, police said.

“It appears to be self-inflicted or accidentally self-inflicted,” McManus said.

(from KENS-5)

He turned the gun on himself, accidentally inflicting a fatal wound to himself after firing at another man's car.

What?

I'm sure there are more details to come, and I'm just curious enough to wonder what they are.