The Farlam Commission of Inquiry investigating the deaths of 44 people in strike-related violence at Marikana in August 2012 started hearing final arguments on Wednesday.
Evidence leader Geoff Budlender, SC, said the commission's purpose was to make findings on accountability, help with the healing process, and help ensure "this never happens again".
He urged the commissioners not to look at the evidence before the inquiry in terms of narrow legal liability.
"Did role players act as they should have? If the inquiry ends there ... it has only gone halfway down the road. Was it appropriate thing to do?" Budlender asked.
At the end of last month, President Jacob Zuma granted the commission its final extension. Public hearings, which began in October 2012, have to be completed by next Friday.
After the arguments, the commission will have until March 30, 2015 to write its report and then hand the findings to Zuma.
The commission is investigating the deaths of 44 people during the unrest at Lonmin's platinum mining operations in Marikana, North West, in August 2012.
Thirty-four people, mostly striking mineworkers, were shot dead in a clash with police on August 16. The police were apparently trying to disarm and disperse them. In the preceding week, 10 people, including two policemen and two Lonmin security guards, were killed.
Budlender said: "Whatever reason shooters fired, presume it was lawful, that doesn't end the inquiry, because if the operation was the result of reckless planning or poor planning, the SA Police Service (SAPS) would be responsible, even if the shooters lawfully fired."
Regarding the killings the week before August 16, Budlender argued the same principle should apply.
"The leaders of strike, even if not legally responsible for the murders... did not prevent what the strikers did."
Budlender said the inquiry needed to consider what had likely happened on a balance of probabilities, and where there was insufficient evidence for this the commission should include its "reasonable suspicions" in its report to the president.
"The commission's task is complicated, as there is reason to doubt the truthfulness of some witnesses."
Budlender said that for him this was "one of the most dispiriting aspects of the commission".
He argued that the police's key witness, identified only as Mr X, appeared to have been less than truthful in some aspects of his testimony.
Mr X, whose identity is being protected as he fears for his life, claimed he was one of a core group of militant strikers who allegedly ingested human remains during a muti ritual they believed would make them invulnerable ahead of the August 16 confrontation with police.
Budlender said it appeared Mr X was biased against the Association of Mineworkers and Construction Union (Amcu).
He submitted that Mr X had, among other things, "invented" the story of Amcu president Joseph Mathunjwa visiting the koppie in Marikana where the strikers had gathered on the night of August 14.
He argued that Mr X tailored evidence to fit the SAPS's case and his own purposes.
"The problem is you don't know when he is inventing and when he is telling the truth. We don't say all of the evidence of Mr X is a lie.
"The SAPS response to this not entirely clear," he said.
Some of Mr X's evidence was corroborated elsewhere, he added.
"One just doesn't know what he was told and what he was trying to do."