Boston Globe | By Brian Ballou and John R. Ellement | March 13, 2013

The attorney for an 18-year-old Roxbury man accused of participating in a group attack Saturday on an MBTA bus driver said today that her client punched the driver, but only as an instinctive reaction after he, too, came under attack by the group.

Albert Galloway pleaded not guilty today in Dorchester Municipal Court to charges of wrongful interference with a bus, assault and battery with a dangerous weapon (a shod foot), assault and battery, and fare evasion, and was ordered held on $15,000 cash bail by Judge Robert Baylor.

His defense attorney, Andrea McGeehan, said in court that Galloway should be treated not as a criminal suspect, but a victim of a violent assault. She said Galloway has no criminal record and attends the Community Academy of Science and Health.

She said Galloway was riding on the Route 16 bus when the attack took place. He was simply trying to get off when he suddenly started being physically assaulted by the same group of about 15 people attacking the driver.

McGeehan said that after being struck from behind, Galloway wheeled around and threw a punch that unfortunately landed on the driver. Galloway was not part of the group attacking the driver, she said.

But Suffolk Assistant District Attorney Michael Callahan said Galloway was among the attackers while providing some new details of the incident that played out early Saturday morning near the intersections of Columbia Road and Geneva Avenue.

Callahan said the incident was a “violent assault by multiple individuals on someone trying to do their very tough job late at night. This was a cowardly act.’’

He said the MBTA bus was traveling on Columbia Road when the driver saw a cluster of 15 or more teenagers trying to flag him down. Concerned that some sort of an emergency was underway, the driver pulled over and opened the door to the bus, Callahan said.

At that point, some 15 people charged onto the bus and began physically assaulting the driver, while another group stayed outside and began attacking him through the window on the driver’s side of the vehicle, Callahan said.

Callahan said a second wave of attackers flowed onto the bus, and kept up the assault on the driver, an assault that only began to ebb when he was able to contact MBTA dispatchers and ask for help.

Callahan also said that during the fracas, a woman passenger threw a Charlie Card at the driver.

Callahan said that investigators were tipped off to Galloway by someone who reported the teenager was talking about participating in the beating. He also, according to Callahan, made a potentially incriminating tweet on his Twitter account.

“My hands hurt from last night,’’ Galloway allegedly tweeted. But McGeehan said there is no proof that Galloway actually posted the comment.

The 53-year-old driver was transported to Boston Medical Center, where he was treated and released. So far this year, there have been 22 cases of T drivers reporting that they were assaulted or threatened. Through the same period in 2012, there were 18 such cases, according to Transit Police.