Natalya Garkovich, 43, from Belarus, can be seen walking onto the platform at Rome's central Termini station. She appears lost or unsure and after getting onto the train she tries to get off again.
But the doors close too quickly and trap the straps of her handbag, and she is carried along in front of dozens of horrified passengers.
Train driver Gianluca Tonelli was unaware that the doors' sensors had failed and Ms. Garkovich was being dragged along the platform.
"I know that I was wrong and I am devastated by what happened to that woman but in the video it can also be seen that I looked twice in the mirror, I was not reckless," insisted Mr. Tonelli.
A man can be seen trying to free her from the door as the train starts to gather speed.
Although the incident is under investigation Mr. Tonelli is not believed to have broken any rules.
"The lady made a strange maneuver up and down, the security system has not reported anything to me and I left. Now the most important thing is that she recovers soon," he said.
Ms. Garkovich broke her back and suffered a punctured lung when she was thrown clear of the train. She was in intensive care for several days but her life is not in danger.
Several passengers reportedly pulled emergency alarms on the train, but they failed to stop it, and Mr. Tonelli was only made aware of the incident when he pulled into the next station.
"The emergency systems on board must function properly," said Carlo Rienzi, of the consumer rights group Codacons.
"We consider it outrageous and offensive to say the train driver is entirely responsible, when you should thoroughly investigate the Rome subway security systems and their proper operation," he added.
"If the trains were equipped with cameras in the cockpit it might have been different," said Stefano Bottoni, national secretary of the Sul trade union.
Earlier this year a three-year-old Chinese girl miraculously survived after she fell into the gap between a train and the platform at Xining station.
