New York - A motorcyclist accused of smashing a window and catalyzing a bloody encounter between a group of bikers and an SUV driver was arraigned Sunday on gang assault and other major charges, while his lawyer said the motorcyclist's role in the headline-grabbing case was unfairly overplayed.

The fourth person arrested so far in a case held up as a highway nightmare, Reginald Chance, was being held on $75,000 cash bail. Prosecutors said he played a key role in the SUV driver's beating, which came after the driver ran over a biker in what the motorist's family said was fear for his life.

While Chance didn't participate in the beating, by shattering the SUV's driver's-side window, he "set into motion a chain of events that resulted in the driver being dragged out of his vehicle and beaten" by others, Manhattan Assistant District Attorney Samantha Turino said.

Chance's lawyer, Gregory Watts, acknowledged his client broke the window in a burst of anger after the SUV's door struck him earlier in the encounter that went from a Manhattan highway to a neighborhood street. Video shows Chance then got on his motorcycle and left, and he didn't hit SUV driver Alexian Lien or encourage anyone else to do so, Watts said.

"This is not a man riding around assaulting people with a quote-unquote 'gang,"' Watts said. "We will hotly contest those allegations."

In a Sept. 29 encounter seen partly on online video, a group of motorcyclists participating in a rally crossed paths with Lien, who was out for a drive to celebrate his wedding anniversary with his wife and their toddler. One biker, Christopher Cruz, cut off the SUV and slowed in front of it, and it bumped his motorcycle's rear tire, police and prosecutors said. Cruz is fighting misdemeanor charges including unlawful imprisonment.

Cruz and other bikers stopped and approached Lien, 33; who drove off, running over biker Edwin "Jay" Mieses Jr. and breaking both his legs and spine. The motorcyclists chased Lien off the highway and onto a street, then attacked him when he got stuck in traffic. Chance's bike was knocked down along the way, when other bikers tried to get at the SUV and it drove on, Watts said.

Later, after the SUV's window was broken, Lien was dragged out, beaten and stomped, needing stitches, authorities said.

Another rider accused of participating in the beating, Robert Sims, 35, of Brooklyn, was arraigned Saturday on charges including gang assault. His lawyer, Luther Williams, said Sims denies the charges.

Prosecutors have declined to charge a fourth man who was arrested, at least for now.

Lien has not been charged with any crime. His family's lawyers declined to comment on Chance's arrest.

Meanwhile, a bystander hailed as a good Samaritan in the episode gave a public account Sunday of stopping the attack.

Lien was on the ground when bystander Sergio Consuegra stepped in between him and the bikers, Consuegra recalled at a news conference with local officials who called him a hero.

"I felt intense danger at that moment, at that time, and I say to myself, 'Let me not show these people that I'm here to engage in any kind of confrontation but that I'm here to protect the man and the family, so I'm going to keep it cool."' said Consuegra, who's in his 50s and had been on his way to church when he saw the encounter.

He spread his arms to signal he was shielding the driver and told the bikers: ''That's it, guys. Let it go. That's it. Let it go," he said. The bikers backed off, and Consuegra called the police.

He said he felt he'd done the right thing. But "I do not call myself a hero," he said, "because I wish I could have done more.