"I am absolutely amazed by how absolutely stupid the guy is. Bloody irresponsible behaviour to the first degree, I can't believe it," he said.
An email complaint had been sent to the bus depot about the incident, but it had not provided enough information for management to act, he said.
"But once we saw the video then it was a really simple thing after that."
He was not able to discuss details of the disciplinary process, Mr Ritchie said, but assured the driver "will be dealt with".
"As far as I'm aware he's been brought in and his manager is dealing with it. I don't know what he's had to say for himself."
The manager would take into account his employment history and whether he had any previous complaints laid against him, Mr Ritchie said.
"The people on that bus put their trust in him. He wasn't even trying to hide it, he was holding the whole newspaper open, over the steering wheel," he said, adding the man's actions were "negligent at best".
"He's betrayed the trust of his passengers more so than anyone else. Can they possibly have confidence in a guy who would do something as stupid as that?"
He added: "From our perspective it's just totally unacceptable, it really is."
A warning would now be issued to staff about distractions at the wheel, he said.
"Certainly I would say 99.999 per cent of them [the drivers] would be horrified to think that that would happen," Mr Ritchie said.
"Generally they're pretty bloody responsible."
He added: "I'm just completely embarrassed by the whole thing to be honest, and all I can say is all of the drivers, I would have thought, would know better.
"I hope they do know better, but we'll reinforce that over the next day or two and remind them of it."
A spokesman for Auckland Transport called for the incident to be investigated.
"Clearly this sort of behaviour is totally unacceptable," he said.
"We have raised the matter with the bus operator and have asked for an urgent investigation."
Bus driver's union, First Union, said it condemned such behaviour.