Toronto police are investigating after a TTC operator allegedly punched a man in a dispute over an unscheduled stop on an express bus, leaving the man so badly hurt that he claims doctors have told him he now has a blood clot in his brain.

Joseph Kau says he unwittingly got on the 511 Exhibition bus headed straight for Bathurst Station Sunday night from Exhibition Place, not realizing it was a direct route with no stops in between until he asked to exit at College Street.

About 10 minutes before they reached the station, Kau says he requested a stop.

"When I rang the bell, he did not stop, so I got up from my chair, and I squeezed between people and I went to the driver, and I'm like, 'Sir, sir, will you please stop?'"

'Everyone just ran'

"Are you an idiot?" he alleges the driver said to him. "You don't see it's an express bus?"

Kau says he didn't want any trouble but wasn't thrilled with the response and became upset. But, he says, he held his tongue until they pulled into the station.

What happened next is now under investigation by the police.

Joseph Kau says he unwittingly got on the bus Sep 3 headed straight for Bathurst Station Sunday night from Exhibition Place, not realizing it was a direct route until he asked to exit at College Street. After a confrontation with the driver, he claims he was punched in the head. (Michael Charles Cole/CBC)

When the bus arrived at the station, Kau says he went back to the driver and said, "You're the idiot one." As he turned to walk away, he says the driver stood up and punched him in the head.

"Bang, my face … Blood dropped from my face," Kau told CBC Toronto. "People in the bus, they screamed, 'He can't do that!'" One woman yelled, "I'm going to call 911!"

CBC Toronto spoke with one witness who did not want to be identified out of concern for her safety.

"As soon as he did that, he punched him, there was like an exodus. Everyone just ran from the bus through the back door," she said. "I was completely speechless, because you normally hear it the other way around, a passenger assaulting a driver."

Driver allegedly 'retaliated,' TTC says

The witnesses alleges when she announced she was calling police, the driver threatened to punch her too.

"I said, 'I'm grabbing my phone to call 911 because this is not right,'" the woman said. "And then he said, 'Go ahead… And if you come near me, I'll punch you too.'"

The TTC wouldn't comment on that specific allegation, saying it will have to review surveillance footage from the bus. But it claims the rider spat on the driver, who then allegedly "retaliated in some way.

TTC spokesperson Brad Ross says the transit agency is investigating. (Michael Charles Cole/CBC)

"To have someone spit on an operator is pretty disgusting and is something that we do not tolerate and something in fact that the Criminal Code does not tolerate," spokesperson Brad Ross told CBC Toronto, adding TTC employees endure on average one assault per day.

Word of the alleged assault comes just one day before the TTC launched a public awareness campaign and accompanying app for transit users to report incidents of harassment to transit control using their smartphones.

Kevin Morton, the secretary-treasurer for the Amalgamated Transit Union Local 113, also defended the driver.

"The operator responded, got up, defended himself. And it's about time that people realized that we're not pin cushions, we're trying to do our jobs," Morton said.

Morton says the TTC has suspended the driver with pay. The TTC would not confirm that Wednesday, saying it was too soon to know of any decision around discipline. "Having said that, we wouldn't discuss [it] anyway," Ross told CBC Toronto.

For its part, Morton says the union will be filing a grievance.

"He didn't do anything wrong," He has a right under the Charter of Rights to defend himself. And we're not going to be sitting around taking abuse — physical, verbal, mental. We're not going to do it."

Ross says the driver reportedly offered to let Kau off at his desired stop after the trip to Bathurst station was complete, but that a stop during the express trip was unauthorized. Nevertheless, he said, the transit agency is investigating.

"We don't want our operators obviously getting involved physically with customers. That's what police are for; that's what special constables are for."

'The video will show everything'

Kau denies allegations he spat on the driver. The witness who spoke with CBC Toronto also says she saw nothing of the sort.

"There's no way, I did not see that at all," she said, adding she hopes video and audio of the incident will surface. "If you can only listen to that gentleman asking him to stop, he was not irate at all. So if they say, 'He was irate at our bus driver,' I'm sorry, I'm telling the truth; he was not irate at all."

CBC Toronto could not independently confirm that Kau is suffering a blood clot, but medical records show he went to hospital Sunday night and was then called back for a CT scan Tuesday. It was recommended that he follow up with his family doctor.

Police say no charges have yet been laid against either Kau or the driver, but that they aren't ruling out the possibility.

For his part, Kau says he is looking forward to the surveillance footage emerging to corroborate his story.

"The video will show everything," he said.