So this is not a woman who will be affected by the bells and whistles that come with a murder accused who's a double amputee and an international athlete and a hero to many.
She was always going to have the same empathy for Reena Steenkamp, a gorgeous model and presenter and much-loved daughter, as she does for any of her domestic violence victims from Soweto.
But her intellectual rigour prevented her from being swayed by cheap emotion. The evidence wasn't there to convict Pistorius on murder charges, so she didn't.
Pistorius was on trial for murder, but Masipa was on trial, too. Historically, judges around the world have been in similar positions -- judges who have known that their every word, every intonation, would be analysed and scrutinised and who would have their judgments consigned to history for future generations able to do retrospective analysing and scrutinising.
No opportunity to go back and polish it up a bit for Masipa. When you're in the hot seat, as she most surely was, in the murder trial of one of South Africa's most famous sons, you have only one chance to get it right.
And in the opinion of this layman, Masipa, a 66-year-old woman raised in Soweto as one of 10 children, a former tea girl and nursing assistant, surely did.
During the six-month trial, I believed Pistorius was a cold-blooded murderer, another in a long line of men who could not and would not believe that their partners would dare to challenge them. And I still believe that now, in my heart.
But this week, Masipa quite rightly ruled against premeditated murder and murder. She said the state had to prove premeditated murder -- and they failed to pass the legal standards to do so.
Listening to her judgment, it was hard to argue. Her sense of the dramatic is impeccable, it must be pointed out. When she delivered her verdict that the state had failed to prove premeditated murder, Pistorius slumped, sobbing and shaking in relief. My lady, as the court refers to her, waited a beat. "There is still, however, the question of culpable homicide. We'll take a short break." And she picked up her robes and departed the bench.
It was electric for those of us watching on television thousands of miles away -- I can't imagine the effect in the court room. After an adjournment, she returned and proceeded to excoriate Pistorius and his legal team's shotgun approach to his defence.
They had offered a number of different reasons for why he might have shot through the door of a tiny cubicle without identifying who was in there, and Masipa dismissed them.
She was contemptuous, in her clinical, judgey way, of Pistorius' snot and tears during his performance on the stand. She found him an unreliable witness and more interested in how his answers would be perceived than in answering questions honestly.
And yet, you can't convict someone for being an asshole. (My words, not hers). So she set aside Pistorius' dramatics and focused again on the law.
Would a reasonable person pick up a shotgun and blast the bejesus out of a tiny toilet cubicle when they heard a noise in the middle of the night, she asked (not in so many words)? No, she decided. Not when you had time to summons the security guards who protected your apartment. Not when you could ring for help on your cellphone. Not when you could have run to your balcony and called for help which, within your gated community, would have come quickly. A reasonable person would not have acted as Pistorius did.
There was a pause and those in the courtroom and watching around the world waited with bated breath. The only possible verdict she could deliver was culpable homicide -- what we call manslaughter. She did, and Pistorius will be sentenced next month.
Pistorius will be sentenced next month.
No amount of jail time will assuage the pain of the Steenkamp family. But they must take heart from the fact that the judge didn't just apply the law when it came to trying their daughter's killer. She delivered justice. And as we know, you don't always get that in a courtroom.
Kerre McIvor is on Newstalk ZB, Monday-Thursday, 8pm-midnight