She said the testing officer, from the company's Penrose branch, mocked her when she asked him to stop yelling at her.
"I know some people are just grumpy, but this guy, he screamed and yelled at me most of the test. I am not big, and he was a large middle-aged Kiwi guy and he was so loud. He wasn't just raising his voice, he was screaming at me."
Terrified, she pulled over and asked the tester to stop yelling.
"But there was no change - he even mocked me, saying, 'Awww, please don't yell at me'."
Assuming he would fail her, Mrs McKenzie followed instructions to return to the testing station. She said that, once there, the tester asked her if she was going to "take it any further".
"I said no, because I thought I had failed anyway and they [Driver Licensing] would just think I was saying it because I had failed. But then, when I said 'no', he ticked pass."
Mrs McKenzie, who arrived from Japan four years ago, waited until her licence arrived in the mail before sending details about her experience to the company.
Customer inquiry official David Brown wrote that the tester "emphatically denies your allegations that he was grumpy and angry".
"The testing officer has been extremely lenient and used his discretion, as he could have marked your test with an 'immediate fail error'," Mr Brown wrote.
Dissatisfied, Mrs McKenzie wrote to the Transport Agency, which told her it took her complaint seriously and had arranged for cameras to be fitted into any vehicle the tester used so Driver Licensing could monitor his behaviour.
Agency official Noel Woodley told her the officer had "a brusque and forthright delivery of instructions that could be misconstrued as him being grumpy and/or angry".
Transport Agency spokesman Andy Knackstedt said in-car cameras were standard training and auditing tools which "may also be used to more closely monitor a testing officer following the receipt of a complaint from a customer".
- additional reporting Mathew Dearnaley