"The stories at the time of Steve's death — none of them were accurate because no one else was there," Lyons said in an interview Wednesday. "And that always bothered me."
Lyons is also speaking out now because he has just finished producing a documentary, "E-Motion," which examines the impact that repressing negative emotions can have on the body.
"I thought that it was a great way to illustrate my experience with Steve; holding onto these traumatic events can be very, very bad," he said Wednesday. "I'm happy that I've finally spoken about it publicly. It has been, I guess, a weight on my shoulders."
Lyons still vividly remembers the day he lost his friend, who rose to fame via his TV series, "The Crocodile Hunter." The two were shooting a wildlife documentary in the Great Barrier Reef when they spotted an 8-foot-wide stingray.
They had been filming the creature for several minutes in chest-deep water and decided to try and get one final shot of the stingray swimming away. Suddenly, the animal began wildly stabbing Irwin with the barb on its tail — hundreds of strikes within seconds, Lyons said. The barb went through his chest "like a hot knife through butter," piercing his heart, Lyons said.
"It probably thought that Steve's shadow was a tiger shark, which feeds on them very regularly," Lyons told Studio 10. "I didn't even know it had caused any damage. It wasn't until I panned the camera back that Steve was standing in a huge pool of blood that I realized something had gone wrong."
Lyons and his crew threw him into their boat and put pressure on the gash over Irwin's heart, which was seeping blood, and Lyons performed CPR. But the damage was too severe. The 44-year-old died later that day, leaving behind his wife, Terri, and two young children.
The fact that Irwin — who was notorious for his extremely close encounters with crocodiles, sharks and other potentially lethal animals — died after a run-in with a normally docile creature shocked the public. But Lyons said he always had a sense his friend would meet an unusual end.
"It was never going to be a croc or a shark," he said Wednesday. "He was so good with animals."