Mr McQuillan isn't sure what got caught in the doors and he barely recalls being pulled from his chair and on to the ground.
"I was too shocked and it happened so fast ... The last thing I remember was I was getting dragged and that big front wheel was just coming straight for my head."
The couple who had stepped off the bus came to his aid immediately and helped him back into his chair. "They were just absolutely stunned."
The impact left him with a bleeding knee, grazed arms, bruising and back injuries.
He stopped the next bus to get details to make a complaint, but was unable to ascertain which company operated the bus that injured him.
He said he had laid a complaint with the police, and a spokesman for Auckland Transport confirmed to the Herald that the council-controlled organisation was investigating.
Mr McQuillan held more than a dozen different classes of drivers' licences before he was paralysed in a crash while on army service.
"The first thing he [the driver] should have done was check his left-hand mirror ... Had he done that, he would have seen me. I can only assume he didn't see me - because he sure as hell didn't stop."
Mr McQuillan, who was still distressed yesterday when describing the incident, was all too aware he could have died, especially if he had been dragged beneath a wheel.
"I'm very upset about it. The guy is meant to be a professional driver. Okay, I got a few bruises, but it could have killed me."
CCS Disability Action chief executive David Matthews said the incident served as a reminder that bus operators should not put timetables before the safety of passengers, disabled or not.
He said companies also needed to ensure their drivers were trained to meet the needs of disabled passengers.