The serious crash analyst was needed at a scene — his third serious or fatal crash in 24 hours.
The weekend of December 5 and 6, two people were killed and another person was critically injured throughout Otago and Southland.
"I just finished up one, just got into Green Island when they asked me to go to the Clinton Highway. I got home from that one about midnight, was asleep for about 45 minutes then got called for the Invercargill one."
Originally from California, Mr McGilbert joined the police upon moving to New Zealand with his wife.
He has been a crash analyst since February 2016, and is one of three in the Southern region.
The role was essentially to determine how and why a crash happened, he said.
There was a lot of maths involved — he had had to do courses in trigonometry and physics.
When he arrived at a scene, he did an initial walk-through of the area to get a rough idea of what had happened.
He then surveyed the scene to determine measurements, and did skid testing to work out the friction of the road.
Part of the job was separating what people said had happened from the evidence.
"On the face of it people are helpful, but I just try to piece together some things.
"You kind of have an idea, but not an answer."
If the crash happened at night, he would go back in the morning for a second look in the light.
A photographer would walk through the scene with him, taking photos for evidence.
He had to gather as much as evidence as he could at the crash site, because once he left, the road was reopened.
Then his attention turned to the vehicles involved.
They were usually towed to a secure site, where they could only be accessed by police.
Often they would be tested for mechanical issues that might have contributed to the crash.
Unless a car was seized through a warrant, Mr McGilbert only had seven days to examine it before it had to be released.
Once he had come up with a conclusion, he would get another analyst to check the evidence.
It could be a slow process, but it was a necessary one.
His work was generally supposed to be completed within six weeks, but there could be a backlog; he recently had seven crashes in a month.
"You want to get it right, you want to be as accurate as possible."
Crash scenes could be emotional, but Mr McGilbert had to block that out to focus.
"You do feel for them, but you’ve got a train of thought that you don’t want to lose."
As he re-created what happened in a crash, it could be frustrating to see how preventable they were.
"Then I think about my family and friends, and think ‘I hope this doesn’t happen to them’. I’m always thinking about it."
Then there were the cases of just bad luck, being at the wrong place at the wrong time.
One of the crashes that really stuck out to him was an incident in early November, in State Highway 1 near Waikouaiti.
Den Thi Baird died after a tree toppled on to the car she was in.
Mr McGilbert often drove past the site.
"It’s awful, for one. And you’re just minding your own business and a tree falls on you.
"Anything can happen."
His main message was for people not to be in a rush.
"Just slow down and be aware of your surroundings. You’ll get there in the same amount of time."
