An angry and excitable Thandi Maqubela killed her husband Patrick after he made it clear he wanted a divorce, the Western Cape High Court ruled on Thursday.

Judge John Murphy found her guilty of the acting judge's death in Cape Town on June 5, 2009, despite not having conclusive medical evidence pinpointing a cause.

"At best there exists a mere possibility that the deceased was suffocated after being subdued or restrained by undetectable means, chemical or physical," Murphy said.

"But even here we are in danger of drifting into the realm of speculation."

Proof of the exact means of death was not, however, a prerequisite for conviction. Murphy said death from natural causes or suicide was excluded primarily by Thandi Maqubela's conduct, a plethora of lies and her persistence in "irrational subterfuge" which was wholly incompatible with an innocent person.

She was found to have told no less than 30 to 40 lies both in and out of court.

The court found that Patrick Maqubela's serial adultery had brought the relationship to an explosive point in 2009. He was in a distressed state and confided to others the day before he was killed, on June 4, 2009, that he wanted to divorce his wife.

"Accused one was in a vengeful and destructive mode," said Murphy.

"She had appointed private investigators to investigate his private life, had threateningly confronted his lovers and had disgraced him in the eyes of his friends, relatives, and colleagues."

Justice Minister Jeff Radebe saw her hours before the death and described her as angry and excitable.

Murphy said Thandi Maqubela's propensity to become excitable when challenged was demonstrated more than once during her testimony.

She was also found guilty of forging the will of her husband and committing fraud by causing potential prejudice to his estate. Murphy said it was unlikely Patrick Maqubela would have left almost his entire estate to his wife, and disinherited some of his children, when considering the state of his marriage.

"The inescapable conclusion is that exhibit D [the alleged will] was not drafted by a lawyer," Murphy said.

"It is even more unlikely that a professional attorney of many years' standing, with extensive experience in commercial law, employed at a reputable firm of attorneys in Johannesburg, and serving as an acting judge at the time, would have drafted such a will or put his signature to it."

Maqubela's co-accused and former business colleague, Vela Mabena, was acquitted on the murder charge because the evidence against him was not as strong.

The State had not proved his involvement beyond reasonable doubt and the acquittal was based on a finding of "not proven" rather than "factual innocence".

"The mere fact that accused two [Mabena] probably knew of the demise of the deceased and acted suspiciously before giving his statement to the police is not sufficient to conclude beyond reasonable doubt that he participated in killing the deceased," Murphy said.

Mabena left the dock and Maqubela stood alone as a swarm of photographers jostled for position around her. She handed a large, black leather bag and a pink file to her daughter and hugged her.

A policewoman gestured to her to put her hands behind her back. She smiled and complied before being led down to the cells.

Outside court, Patrick Maqubela's first wife, Nzwaki Maqubela, said her heart went out to his children and family.

"It is a relief to the family and to all who liked him... [Thandi must get] the longest sentence because she is a danger to the community," she said.

Maqubela would remain in custody until her sentencing on November 20.