"I saw two guys fighting about 20 yards away, 30 yards away at the most. And I thought, oh great, another punch up on the street. And then bang, bang, bang," Windle said.
RELATED: What experts say 49ers WR Ricky Pearsall's recovery might look like after being shot in the chest
That scuffle and shooting Windle witnessed involved 49ers rookie and first-round draft pick, Ricky Pearsall.
Pearsall was shot through the chest after a 17-year-old attempted to rob him while he was walking down the street near Union Square.
The incident happened just hours after he appeared at an autograph signing event just miles away.
"It was at the moment, just simply shocking. It wasn't until later that I began to shake," Windle said.
RELATED: Video shows 49ers' Ricky Pearsall escorted to ambulance after San Francisco shooting
Video shows 49ers' Ricky Pearsall escorted to ambulance after San Francisco shooting
Windle tells ABC7 News reporter Tim Johns the entire encounter happened rapidly and was over within a minute or so.
He says shortly after the gunshots rang out, he saw police who were stationed nearby running towards the scene.
"The police response was fantastic. They had that place swarmed," Windle said.
The first officer to arrive was Sgt. Joelle Harrell. Sgt. Harrell is being described as a hero, who may have saved Pearsall's life.
ABC News spoke with her on Monday.
Harrell told ABC News reporter Melissa Adan that she heard the gunshots and then went running to find Pearsall on the ground in a pool of blood.
RELATED: 49ers put Ricky Pearsall on NFI list after WR shot in chest during attempted robbery in SF
"I use my right hand, because this is my strong hand, to seal the wound. And then I put it up here to hold that," Sgt. Harrell said.
The sergeant says while they waited for paramedics to arrive, she knew keeping Pearsall conscious and calm was paramount.
She detailed some of their conversation during those critical minutes.
"I know you don't know me but please trust me, God is with us. It's not your time, OK, it's not your time. I want you to continue to breathe. Just breathe," Sgt. Harrell said.
Thanks to Pearsall's description, SFPD was able to identify and arrest the suspect.
The NFL rookie is now out of the hospital and recovering at home.
VIDEO: Here's what political implications shooting of Ricky Pearsall has on San Francisco's mayor race
How Ricky Pearsall shooting impacts San Francisco's mayor race
But the reputational hit the incident has on San Francisco may be harder to recover from.
On Monday morning, we went back to Union Square to talk to tourists about their perception of the city following the shooting.
Almost all of them told us they had heard that the city was unsafe ahead of their visits.
That included Billy Seiba and his family, who are visiting from Texas.
"It was dirty, a lot of hearing about crime and stuff like that," Seiba said.
INTERACTIVE: Take a look at the ABC7 Neighborhood Safety Tracker
Seiba says despite what he had heard, he's been pleasantly surprised by San Francisco. He tells us he and his family have enjoyed their time in the city by the bay and would be interested in returning. He also says, while unfortunate, he thinks the Pearsall incident could happen in any major city.
"I work in downtown Houston and it's a lot worse in downtown Houston," Seiba said.
That opinion is also backed to a large degree by statistics.
According to the ABC7 News Neighborhood Safety Tracker, the robbery rate for the entire city of San Francisco for the last 12 months is down 4% from the previous four-year average.
And in the Central District, which includes Union Square, it drops even further to 6% less than the previous average.