"At the time I didn't know how big all this was," Mr Clarke told Triple M's Big Breakfast.
"I had been working, I wasn't on social media or anything.
"I sort of knew what happened – there had been an accident. My wife had called me to say, look, just come home, I knew sort of what happened, I just didn't know the whole world knew."
He was working more than 1000km away in Moranbah so had to tell his bosses he had to go.
"They were just like, 'Mate, you're on a plane straightaway. No if, buts, or maybes, we're getting you home even if we have to charter a plane for you'."
Mr Clarke said he found their reactions a "bit weird" and it wasn't until he returned home to Brisbane that he realised why.
Ms Clarke succumbed to her injuries that night after receiving burns to 90 per cent of her body.
Her three children Laianah, 4, Aaliyah, 6, and Trey, 3, all died at the scene. Their father Rowan, who had set the car alight, stabbed himself to death.
Ms Clarke's family said her injuries were so severe only her footprint could be recovered.
Mr Clarke told Nine's A Current Affair said they wanted her footprint to be a symbol for her and her legacy.
He told Triple M there were times they thought Baxter's behaviour was strange but they didn't think much of it.
"There were certain things he did that you sort of question … but you sort of let it slide," he said.
"I think that's the worse thing about this sort of domestic violence – they sort of make the other half play their part. My sister would always play it (his behaviour) down.
"The worst part of this type of abuse is that you can't see it. You get those feelings, but because you can't see it, you don't know.