"I'm sorry my Lord, I must ask, am I on trial here?" Nassif said as defence attorney Laurence Hodes SC, questioned him about drug charges he faced in 2007.
Judge Frans Kgomo responded that the line of questioning spoke to his credibility as a witness in the trial underway, and allowed proceedings to go ahead.
Hodes pointed out to the court that Nassif was a section 204 witness in the drug matter – meaning he would receive indemnity from prosecution provided his testimony was honest.
He said Nassif had to then enter into a plea bargain after he had "lied" in his statement.
Nassif replied that he had not lied but merely left out information in his statement. He was advised to plead guilty for a lighter sentence in the drug matter by his attorney.
Hodes told Nassif that his conduct in the drug matter was similar to his conduct in the trial of drug trafficker Glenn Agliotti who is facing a murder charge.
Have a full go
Nassif is a section 204 witness in the Agliotti matter.
The burly witness who took frequent sips of water during the fourth day of cross examination challenged Hodes to "have a full go".
"Mr Hodes, it’s my fourth day, I'm willing to stay here (in the witness stand) for six months, have a full go."
To which Hodes replied, that Nassif's comments did not "impress" him and told him he could stay in the witness stand for a year but it would mean nothing if he continued to evade the questions.
Agliotti was sombre as he sat in the dock of court 4C during the second week of his trial in which he is facing four charges – two counts of conspiracy to commit murder, one of attempted murder and one of murder.
In an adjoining court his one time friend former police commissioner Jackie Selebi heard his sentence of 15 years in prison.
Agliotti, who was a section 204 witness in the Selebi matter, had no comment on the sentence.