Two Dreamworld workers have been brought to the inquest following the October 2016 tragedy.
Wayne Cox was the engineering supervisor and admitted that on that day he didn't know the ride had many malfunctions.
Cox had misheard the radio, which he thought said a "Code 6" - which is a breakdown. What actually had been radioed in was a "Code 222 Blue" which means medical emergency.
By the time he and fellow engineering supervisor Scott Ritchie got to the ride, Dreamworld's first responders were already there - and unable to do anything to the four victims who were crushed to death.
Mr Cox recalled that they ran about two thirds of the way through the park before slowing to a walk “so as to not draw too much attention to ourselves and alarm the park guests”.
The inquest is for the deaths of Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi.
The primary cause of the incident is believed to be when a water pump on the ride malfunctioned, causing the two rafts to collide and flip.
The inquest heard Dreamworld had commissioned Products for Industry (PFI) to undertake a safety upgrade on the 30-year-old ride.
The upgrade, completed in February 2016 with some additional works in March, cost about $19,000.
Michael Takac, who worked as an electrician for Applied Electro - a company that has maintained many Dreamworld rides since 2011, also spoke.
Mr Takac recounted how in June 2016 he was doing his annual check but was unable to complete it as the ride’s south pump was down for maintenance.
The theme park told him "look, it’s running, the device is fine”.
“So, we left it,” Mr Takac told the inquest.
After receiving a call three days before the incident about an issue, Mr Takac told the inquest he was unable to go and see the ride as he was fixing his phone but his boss advised "it didn't sound urgent".
Mr Takac says he thought the ride should halted: “My advice would be to stop the machine and not use it, to investigate deeper what the problem is … It’d open up a can of worms but a lot more testing needs to be done.”
According to a report found in the inquest, a safety feature that cost less than $3000 could have addressed the issue.
The inquest continues.