The man was still too upset over the tragedy to be named.
"We saw things we wished we hadn't," he told Newshub.
When the accident happened, his group was in another raft but they managed to climb out while it was on the conveyor belt.
No one alerted them to the horrific scenes unfolding so they made the decision to get themselves out, he said.
Panicked onlookers screamed while some jumped over the barriers to try to rescue the victims.
The man said he was "counting his lucky starts" despite being traumatised by the deaths.
His mother told Newshub the couple would never go to another theme park.