"Oz happened to ask my one mate to see his gun. My mate passed the gun across to him and unfortunately the gun went off. The bullet missed my toe by an inch. I could have lost my foot," Lerena said.
"I've never seen a person's face change so quickly in my life," Lerena went on. "[Pistorius] went pale; he actually started shaking he was so apologetic."
Even freak accidents can be bad for one's image, so the incident was covered up.
"My friend took the fall for [Pistorius] because of his status," Lerena told "Good Morning America." "No one was saying 'protecting Oscar,' but someone else took the fall for us as a friend."
Clearly the "Blade Runner" was a hot-blooded alpha male -- but was he also hot-tempered? Last year, after a series of jealous texts over an 18-year-old girlfriend, police say, Pistorius told another man he would break his legs.
"I was amazed," O'Sullivan said. "I was taken aback. I didn't think Oscar had it in him to make those kinds of threats, to threaten that level of violence."
"He's got his moments of anger," O'Sullivan continued. "Maybe too many people wanting too much from him, and eventually he snaps. ... I could never say these are premonitions of greater darkness to Oscar's personality, though."
"His P.R. machine was very good and covered up his few indiscretions," said Andy Grudko, former South African reserve police officer.
Whatever human shortcomings Pistorius may have had, the image the public wanted to preserve was London 2012, his sprint into immortality as the first double-amputee Olympian.
But weeks later, the Paralympics were held in the same stadium. After a surprising upset, Pistorius' good sportsmanship went out the window. He said that the Brazilian sprinter who beat him at the finish line had an unfair advantage because of his running blades.
"He said it was unfair, and he was petulant about it, and this shocked people," Michael Sokolove said. "He apologized, he said he regretted it. Everybody looks back now: Was this something that changed him, or was this evidence that he had already changed?"
This fall Pistorius told friends that his life had changed -- for the better. That was when he met the gorgeous girl from Port Elizabeth, Reeva Steenkamp.
Friends have testified that Pistorius was deeply committed to the relationship. If anything, they said, his heart was racing faster than Steenkamp might have wanted.
Amid the exhilaration of new love, Valentine's Day was going to be special: flowers, dinner and romantic plans. Reeva Steenkamp's last tweet read, "what do you have up your sleeve for your love tomorrow??? #getexcited#valentinesday"
Watch the full story on "20/20: The Fast Times of Oscar Pistorius" TONIGHT at 10 ET