Former Cosatu general secretary Zwelinzima Vavi and EFF leader Julius Malema are plotting to overthr.
Sello Matlhoko said defence lawyer Johan Nel had pointed a finger at witness Phillip Selokoe as he fired questions at him. Matlhoko said the action was intimidating.
This came after Nel accused Selokoe of being evasive in his answers.
The case is being held in the Ficksburg Magistrate's Court in the Free State.
Selokoe told the court that the pandemonium that broke out before Tatane was killed was sparked by an apple and a plastic bottle that were thrown into the crowd by someone in the municipal building.
Selokoe insisted that a stone that was thrown by a member of the crowd was in retaliation for the apple and plastic bottle.
Nel did not agree with Selokoe on the number of objects thrown into the municipal building but Selokoe stuck to his answer that he saw only one stone being thrown.
Selokoe insisted that his evidence was truthful and that he did not see any other objects as he was running for cover. He claimed that people wanted to enter the council building before police charged at them.
He reiterated that what sparked the chaos which led to Tatane's death on April 13 2011 was an empty plastic bottle and an apple that were thrown into the crowd.
"There were between 4000 and 5000 people at the protest. I first saw an apple followed by a plastic bottle being thrown from the second floor of the municipal building. The bottle hit someone in the crowd and the situation got out of hand," he said.
Selokoe added that he saw a stone being thrown from the crowd and it hit the municipality building's glass door, breaking it.
"Police retaliated by firing tear gas, rubber bullets and sprayed protesters with water from their water cannon," he said.
Nel then accused Selokoe of changing his testimony and contradicting himself.
Nel said Selokoe's evidence-in-chief and his testimony during cross-examination were different.
Police officers Nicodemus Israel Moiloa, Mothusi Magano, Solomon Moeketsi, Mphonyana Ntaje, Isaac Finger and Olebogeng Mphirima have all pleaded not guilty to Tatane's murder.