The dashboard had caved in around them - as the van had fared much worse than the other vehicle, which appeared to be a Holden Colorado ute, he said.
"There was a man and a woman trapped in the white van," he said.
"His airbag had gone off. He seemed to be in much better condition [than the woman]."
She was obviously in a lot of pain and appeared to be in shock, he said.
The group tried to pry open the door using a crowbar, which was supplied by a tradie who had also stopped to help, but they could not shift it, he said.
"There wasn't much we could do. I felt a bit helpless."
Not wanting to make things worse, the group stopped and awaited emergency services.
An Australian off-duty paramedic comforted the woman while they waited, he said.
Meanwhile, another group of people were attending to the people in the ute, he said.
He said he had been shaken up by what happened and later called the hospital to make inquiries after the couple but he was not told how they were faring.
"It's a bit frustrating - you want to know they are okay."
Seven people in total were injured, two of whom were flown to Auckland City Hospital in critical condition.
An Auckland DHB spokeswoman was unable to say how the two people were when asked by the Herald today.
A Waikato DHB spokeswoman confirmed the people who had sustained moderate injuries in the crash had been discharged from the hospital.
