Wa Kgosi said he thought that by taking the lane of the far right, the Corolla was on its way to the car rental parking or taking a shortcut to domestic arrivals.
"I was so surprised because he was travelling at a high speed, but I thought maybe he is rushing for a flight because it was early in the morning," he said.
"In a split second after taking the far right [lane], he went straight into the pillar. The Corolla spun around and the bumper came off. When I drove past, I saw it was badly damaged," Wa Kgosi he added.
The 47-year-old said he initially thought the it was an Uber or shuttle driver because of the make of vehicle.
"I didn't stop because I was with a client. When I came back from the airport I saw some police there and tape around the car," he said.
Wa Kgosi said he saw a picture of the crash trending on Twitter later on Monday, and then realised that it was the same accident he had witnessed.
"This Corolla, I saw it in the morning. That's how I found out it was Gavin Watson," he said.
"There wasn't any distraction in his way. Maybe he was texting and driving, but I don't know."
Gavin Watson was speeding at the time of fatal crash, eyewitness says
The car Gavin Watson was driving was travelling at high speed when it ploughed into a pillar on Monday morning, an eyewitness has said.
Watson died in the crash, which took place under a bridge near OR Tambo International Airport.
Shuttle driver Mphahlele Wa Kgosi said he was on his way to the airport to drop off a client who was on a 6am flight.
"It was early in the morning and there was not a lot of traffic. There was a [Toyota] Corolla in front of me, which was driving in the far right [lane]. I took the far left [lane] for departures," Wa Kgosi said on Tuesday afternoon.
Wa Kgosi said he thought that by taking the lane of the far right, the Corolla was on its way to the car rental parking or taking a shortcut to domestic arrivals.
"I was so surprised because he was travelling at a high speed, but I thought maybe he is rushing for a flight because it was early in the morning," he said.
"In a split second after taking the far right [lane], he went straight into the pillar. The Corolla spun around and the bumper came off. When I drove past, I saw it was badly damaged," Wa Kgosi he added.
The 47-year-old said he initially thought the it was an Uber or shuttle driver because of the make of vehicle.
"I didn't stop because I was with a client. When I came back from the airport I saw some police there and tape around the car," he said.
Wa Kgosi said he saw a picture of the crash trending on Twitter later on Monday, and then realised that it was the same accident he had witnessed.
"This Corolla, I saw it in the morning. That's how I found out it was Gavin Watson," he said.
"There wasn't any distraction in his way. Maybe he was texting and driving, but I don't know."
The car belonged to Watson's embattled business, African Global Operations, formerly Bosasa. Watson had borrowed the company car on Sunday “as his car was in for mechanical repairs", a company representative said.
Police spokesperson Lt-Col Katlego Mogale said the crash happened when the driver allegedly lost control of the vehicle.
A culpable homicide case has been opened.