IT manager Eddie Yeo was crossing the road near his house in Pasir Ris two weeks ago when a bus failed to stop completely and hit him.
Mr Yeo, 42, used his right hand to protect himself, resulting in a fracture.
When the bus driver called him the following day to apologise, Mr Yeo got a further shock.
The driver from bus firm Go Ahead said it was a split-second hesitation in applying the emergency brakes that led to the incident.
He claimed that he had hesitated because every hard braking incident would be automatically recorded by the company and could affect his performance ranking.
Mr Yeo, who was told by a Go Ahead customer service manager to contact its insurers for his medical claims, said he forgave the bus driver and was not seeking compensation from him.
However, Mr Yeo said he hoped that others would not be hurt in similar accidents due to bus drivers' fear of being penalised by their company.
The driver, who has been sacked over the incident, told The Straits Times that he takes responsibility for what happened, and had called Mr Yeo as he felt guilty.
The 42-year-old has more than 10 years of driving experience and had joined the company in September 2016 when it first started operating. He declined to be named.
When contacted, Go Ahead said the driver was no longer employed due to a serious breach of traffic rules "as it falls short of our very high standards".
The company said "positive and negative driving behaviour, including hard braking, (is) automatically recorded to provide bus captains with a performance overview and allow them to adjust their driving behaviour accordingly".
"Bus captains are trained to practise driving behaviour that would not require them to apply hard braking in normal circumstances, and conversely, to exercise discretion to know when it must be applied," said a spokesman.
The firm said using a telematics system to track how a vehicle is driven has improved overall driving performance among its bus drivers.
Go Ahead, which runs 26 services and is based in Loyang Bus Depot, said its drivers are rewarded for good behaviour with cash bonuses and vouchers.
It said it has no policy of penalising drivers based on the use of emergency brakes.
In instances where its drivers have to use hard braking to avoid collisions, "our safety team will look into the matter and identify the cause of such an action".
"Through investigations like these, we have observed a number of cases where legitimate use of hard braking was applied," it added.
The Straits Times understands that all the major bus operators, including SMRT and SBS Transit, have similar tracking systems.