The retired cop accused of fatally shooting a beloved father and Con Ed worker in a road rage outburst Tuesday on the George Washington Bridge was likely charged with manslaughter instead of murder because the attack wasn't planned, according to experts.

Koran Irvine's grieving family questioned why ex-NYPD detective Victor Romero was hit with the lesser charge of first-degree manslaughter for the deadly confrontation that unfolded on the Jersey-bound side of the bridge Tuesday evening after the pair's cars nearly collided.

However, defense lawyer Michael Bachner, who is not connected to the case, said he wasn't surprised by the decision, explaining that prosecutors would struggle to prove Romero intended to kill Irvine.

"The District Attorney's office was under the theory that this arose out of an altercation with some lack of premeditation, lack of planning," Bachner said.

"It was a road rage incident where the guy went to get his gun without an intention to kill. There was no proof there was an intention to kill the guy."

The tragedy unfolded when Romero, 62, allegedly started tailgating Irvine, a 46-year-old father of two, before he pulled up alongside Irvine's car and shot his gun.

Irvine's car suddenly stopped, causing a traffic buildup before it lurched across lanes and crashed into a median 40 seconds later, according to a criminal complaint.

Romero fled the scene and was arrested later, prosecutors said.

With a second-degree murder charge, Bachner explained, prosecutors would have to prove Romero was acting with depraved indifference to human life — a higher legal bar than required with a first-degree manslaughter charge where prosecutors would need to prove Romero intended to cause physical injury, which resulted in death.

"It sounds to me, it smells to me, more like he consciously disregarded a risk rather than he acted with a depraved indifference to human life," Bachner said.

"I see why [Manhattan DA Alvin] Bragg made this decision," the attorney continued.

"I understand the outrage over it, but I think it really does fit more into the manslaughter mold than it does into the murder charge."

Meanwhile, veteran Big Apple defense attorney Robert Gottlieb said he was "surprised" by Bragg's choice.

"Just relying on what's alleged in the complaint, there is more than enough to have charged him with murder," Gottlieb insisted.

"I have seen people charged with murder under less powerful evidence of depraved indifference murder."