“It could be that he wants to lessen his contribution to the incident,” she told the High Court sitting in Palm Ridge on the East Rand.
She said while Robin Harwood might have been aware of his actions, he might not have fully understood the consequences.
Theologo, 18, was doused in petrol and set alight on a hill in Linmeyer in October 2011.
Heath said peer-pressure, alcohol, drugs, and the fact that the incident involved dealing with the devil could have played a contribution to Harwood not backing out.
She said that while Harwood had perhaps agreed to the soul-selling ritual that he and his co-accused embarked on, they possibly could have not digested that it would result in the death of at least one of their friends.
Harwood, Linden Wagner, Courtney Daniels and Harvey Isha are on trial for Theologo’s murder and the attempted murder of her 14-year-old friend who survived the attack.
Two others, Jeremy King and Lester Moody, earlier confessed to the crime and were each sentenced to 17 years in prison, five of them suspended.