He claims that immediately following the incident he lost all cellphone reception, his vision was blurry and his eyes watery for about an hour afterwards.
Mr Robert was driving into Greymouth at the time to pick up his partner, Charlotte Rose, from work at the hospital. He arrived there bug-eyed and agitated.
Ms Rose said he was visibly shaken.
"I just looked at him and I could tell something bad had happened, he was freaked out and his eyes were watery," Ms Rose said.
Coincidentally, Mr Robert had been looking at the night sky in real-time via his smartphone on an app called the Night Sky a few minutes previous.
"I was sitting at home before I went to town and I was looking at satellites and other things on my phone. Suddenly, what looked like a satellite started going crazy and moving all over the sky and I was trying to follow it with my phone."
Mr Robert said he hoped the witnesses from the other cars would also come forward and confirm what he saw. One vehicle was a Mitsubishi Chariot and another a Honda Accord. He did not have a description of the third vehicle.
"I know people are going to think that it's crazy, but I know what I saw."