The woman who trained a junior operator at Dreamworld how to work on a ride that tragically malfunctioned in 2016 believed she knew how to deal with an emergency.
Four people died on the Thunder River Rapids Ride after a water pump malfunction on October 25, 2016.
Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi died after their raft collided with another raft on the ride's conveyor belt.
Courtney Williams was working her first shift as a junior ride operator on the 30-year-old attraction on the day of the tragedy at the Gold Coast theme park.
On Tuesday, an inquest into the deaths was played a video of trainer Amy Crisp explaining how she instructed Ms Williams on the morning of the tragedy.
Ms Williams has already told the inquest she did not know what an emergency stop button near her unloading area did and had been told by Ms Crisp not to worry about the button because "nobody ever uses it".
In the video, however, Ms Crisp felt confident she'd not only explained the button to Ms Williams but that she knew exactly what it did.
"I said if you hit that, it's going to stop the conveyor and your pump," Ms Crisp told detectives before adding Ms Williams had said "yeah, yeah, I get it" in response.
Ms Crisp later told the detectives she couldn't understand how the tragedy happened because there should have been enough time for either Ms Williams or senior ride operator Peter Nemeth to shut down the attraction.
Earlier, attractions supervisor Sarah Cotter, an experienced operator of the 30-year-old ride, told the inquest she believed the ride operator on duty had failed to shut down the conveyor in time to avoid the tragedy.
"There was a raft on an angle - for it to be in that position the conveyor must still have been running through all that time," she said.
"I don't think it was ever stopped, or (it was) just jammed stopped."
She also said that in her opinion an alarm button that would alert park staff to an emergency had not been pushed during the tragedy as it should have been.
The inquest continues.