When Mo Shaik gave evidence at the Hefer Commission, he spoke of a world of shadows - where impressions were more important than facts, and suspicion was enough.

It was a place where logic could get one killed and where a whisper was a more effective shield than a fact.

But when Shaik, driven by loyalty to his erstwhile commander Jacob Zuma, turned the same whisper into a weapon, he found himself on the back foot, defending what seems to have been a dubious decision.

Earlier this year, Shaik revealed that his ANC intelligence unit had once investigated National Director of Public Prosecutions Bulelani Ngcuka, and found that, in all probability, he was an apartheid agent.

With that, he catapulted himself and his reconstructed intelligence report into the world of law.

Over three days, Shaik found himself under the bright spotlights of reason. He was cornered by a trio of some of South Africa's brightest legal brains, with their reverence for logic and proven facts. And he had to watch his whisper about Ngcuka melt away under their complete disregard for his suspicions.

Until his last sentence, Shaik tried to make them understand.

"Life is a strange thing. One thing does not necessarily follow the other because it is logical. The reverse can follow." But they just shook their heads, forcing Shaik to conclude his evidence with tears in his eyes, saying: "If I brought my country into disrepute, I apologise."

It was clear right from the start that the members of the commission and Shaik were not thinking on the same plane.

At the beginning of his evidence, Judge Joos Hefer asked him: "Are you saying that you do not have open permission to deal with intelligence issues?"

Shaik: I also don't have direct instructions not to do so.

And he stuck by his story to the end.

"I still have a suspicion," he said shortly before his cross-examination ended. "If the commissioner can find credible information to disprove my assumption, then I will apologise."

He was clear about his motive.

Marumo Moerane SC, counsel for Ngcuka, asked: Why did you decide that untested allegations should be published?

Shaik: I believed, and still believe, that an unfair investigation was done to discredit the good name of the deputy president. Moerane: You wanted to hit back.

Shaik: I wanted to show that bygones are not always bygones. Ngcuka is using his power to investigate those who investigated him and I was bound by my conscience to do what I believe was the right thing to do.

Moerane: You are blackening the name of an innocent man.

Shaik, who swore by Oliver Tambo's standard that spy information must be as "true as the Bible", filled his evidence with conjecture, speculation and counter-arguments.

"My standard of proof is if there was a reasonable basis for suspicion," he said, but conceded that his report was never meant to be made public. (Notwithstanding later admissions from him that he was the one who gave it to former Sunday Times journalist Ranjeni Munusamy.)

He was slow to commit to a definitive answer about the outcome of his investigation.

Judge Joos Hefer asked him: How would you rate the chances of Ngcuka being a spy?

Shaik: I cannot come to a conclusion that he was not a spy.

Evidence leader Kessie Naidu SC also tried: You cannot say he was a spy. You do not know. Can we commence on that basis?

Shaik: No.

He had enough for strong suspicion, Shaik said.

He had a report from an apartheid agent who reported that he had had breakfast with Ngcuka and told the security police: I think he (Ngcuka) is the ANC representative in Geneva.

He had two reports made by agent RS452. Shaik described the reports as strange and sinister, as was his finding that there had been a possible attempt to generate another ID number for Ngcuka.

Shaik's suspicion was raised when Ngcuka was given a passport, even though he had been arrested by the security police, but he finally conceded when cornered on the issue by Naidu.

Naidu: It was approved before his arrest, and issued after his arrest.

Shaik: It is all I have at this point.

He added that he still found it strange that there was no movement control on this passport. He relied on statements made by people detained by the security police under what Shaik described as tremendous duress.

Naidu: Did you accept the statements as the truth?

Shaik: Not as the gospel truth.

With all Shaik's declarations of loyalty and desire to help the commission, his evidence had a subtle element of vindictiveness. He hit Ngcuka where it hurt the most and apologised only when all was said.

The late lawyer Griffiths Mxenge is well-known as one of the people who played a pivotal role in Ngcuka's life. He named the Scorpions headquarters after Mxenge and his wife, Victoria, who were both killed by the security police.

Of all the evidence led before the commission, the testimony on Mxenge most visibly upset Ngcuka.

Ngcuka worked as an articled clerk at Mxenge's office. Shaik told the commission that the ANC believed Mxenge had asked him to leave because he didn't believe Ngcuka shared the ANC's views.

He added that the ANC later received information from Dirk Coetzee that there was an apartheid source in Mxenge's office.

Naidu: Was it Ngcuka?

Shaik: No sir, don't do that. No, no, no, no. I said there was a source.

Naidu: What does that have to do with anything?

(Later) Moerane: Why did you introduce it?

Shaik: I was trying to be honest.

Moerane: Why did you raise it? You made a suggestion and hoped people would draw inferences.

Shaik: It was not my intention. I am just putting my information on the table. I am at a loss here. It was not my intention to smear his name.

Moerane: Ngcuka was deeply hurt by it.

Shaik: I apologise for it.

Moerane: Mxenge regarded him as a son.

Shaik: I am very sorry.

Moerane: You did not debrief Coetzee. If necessary, we can lead evidence that he never made a suggestion that Ngcuka was the source in Mxenge's office.

Shaik: I apologise unconditionally.

After days of cross-examination, Shaik became deeply suspicious of the demands put on him by super-logical legal teams.

He admitted that he had handed his private intelligence database over to the Ministry of Intelligence on Sunday and handed in a receipt to prove it.

Moerane: This took place yesterday?

Shaik: (looks at Moerane, clearly deep in thought, then realises what the question is) You are asking me for the date, Mr Moerane?

Moerane: Don't be so suspicious, Mr Shaik. It is only a date.

But for Shaik, the arms deal investigation and his evidence had already moved beyond the obvious.

He addressed an absent Ngcuka: You have touched my family. That is OK. You touch Jacob Zuma and that is not OK. I feel deeply about the false investigation against him. It undermined the rule of law and democracy.

And with that, Shaik left the commission, clutching a file filled with nothing but gossip, standing tall on his own moral high ground that was rapidly crumbling under the eye of logic and reason.

With acknowledgements to Estelle Ellis and The Star.