Claims that the attack on a media bus last night was caused by stones rather than gunfire have been dismissed as "spin" by a journalist and former US Air Force captain on the vehicle when it happened.
Lee Michaelson claimed that those responsible must have reached "Olympic-standards" of rock-throwing for this explanation to be true.
Two windows were smashed and three passengers left with cuts and minor injuries after the incident in the Curicica neighbourhood between the basketball venue in Deodoro and the main Olympic Park in Barra de Tijuca.
According to Rio 2016 security chief Luiz Fernando Correa, stones were thrown and hit the metal framework and windows of the bus.
"From a preliminary report, we believe it was a stone and not firearms," he said.
"As to whether it was thrown by hand or something else, we don’t know.
"Stones were thrown and hit the metal part and windows on the bus.
"The victims and the bus were immediately removed from the area...there has been a police report and an investigation is under way."
Michaelson, now a lawyer, is here writing for a basketball wesbite.
She insisted she recognised the sound of gunfire.
"Two shots rang-out," the military veteran said.
"Will have to wait until we see the full forensics and ballistics report, but it sounds to me like they’re looking at the wrong part of the bus.
"They're need to show us this full report before I believe this was any sort of Olympic rock throwing by local teenagers."
Aside from the apparent noise of gunfire, Michaelson claimed the bus was travelling at around 50 miles per hour, meaning remarkable accuracy would have been required to hit not one, but two, windows with a stone.
"It certainly does [sound like spin from organisers] I will apologise to them if I hear a convincing forensics and holistics report examining the right part of the bus from a competent body that doesn’t have an interest in this," she said.
Brazilian organisers will be desperate to avoid any more incidents like this after several security incidents have overshadowed the start of Rio 2016.
On Saturday (August 6), a military bullet was shot into the media tent at the equestrian venue in Deodoro, reportedly coming within two metres of an official from the New Zealand team.
The bullet, identified as a 5.56 milimetre assault rifle round, pierced the plastic roof of the tent before landing close to the area set up to hold athlete press conferences.
Reports have also surfaced today that another shot was fired at stables in which horses were staying at the equestrian centre, adjacent to a military site.
Numerous other journalists and officials, including Portugal's Education Minister Tiago Brandao Rodrigues, have also been mugged at gun or knifepoint during the Games.
Correa said that they are preparing "additional security measures" today and carrying out a full investigation.
Michaelson highlighted other concerns, however, including how the driver initially tried to stop the bus following the attack, rather than automatically driving clear.
The lights of the bus remained on, she also claimed, illuminating the vehicle and making it more of a target.
Michaelson also revealed that she and others involved have not yet been questioned by Brazilian officials and that she was forced to perform rudimentary first aid on one passenger because they had no assistance
Officials today were not able to answer the question of whether the driver of the bus was a full-time employee of the company or a volunteer.
They claimed their preliminary investigation did not cover this.
The investigation is still ongoing, however, and organisers have vowed to publicly disclose more information as it appears.
"Other than mobile patrolling, we are going to have a fixed team in position [where the incident took place] and additional measures that are being prepared," added Correa.
Rio 2016 director of communications Mario Andrada was also forced to defend his seemingly ill-advised prediction that Rio would be the "safest city in the world" during the Games.
"I don’t regret saying that, that’s our mission," he said.
"When an athlete says he's going to win and doesn’t win, he doesn't regret saying that.
"We are convinced that we can guarantee the safety of athletes, journalists, fans and volunteers - that’s our primary responsibility."